As if running a blog dedicated to plesiosaurs isn’t geeky enough, I admit to being a toy collector as well. It isn’t a secret that I run a second website (dinotoyblog.com) (and forum) dedicated to dinosaur figures, and since launching that site it has become apparent that there is a surprisingly large community of dinosaur toy collectors. I say ‘toys’, but collectors often refer to them as ‘museum quality replicas’ or ‘scale models’, although this is most likely an attempt to justify what is clearly an unhealthy obsession with plastic animals. The majority are far away from ‘museum quality’. While I’m no completest in general, I suppose when it comes to marine reptile figures I am – my apartment is strewn with plesiosaurs, ichthyosaurs, and mosasaurs.

Small marine reptile figures (click pic for larger image)

With the advent of Ebay and internet stores it has become all too easy for things to get out of hand! As new figures are released every year, we’re doomed to be collecting for eternity. Anyway, I though I’d share these snaps of my marine reptile collection as it stands, for you to admire or mock depending on your point of view!

Large marine reptile figures, and a few oversized books. (click pic for larger image.)

A couple of new plesiosaur figures will be released in 2011, both from blossoming company CollectA. As a UK-based company CollectA has a tendency to choose British taxa, sometimes rather obscure ones. So forget Elasmosaurus or Kronosaurus, CollectA have gone out of their way to produce the first ever replica of two wonderful British Jurassic taxa: Rhomaleosaurus and Attenborosaurus.

Rhomaleosaurus was the subject of my PhD project so it’s fantastic to see it turned into a toy. I’ve written a full review of this figure over at the dinosaur toy blog (here)

I’ve discussed my favourite plesiosaur Attenborosaurus here on the blog before, as I’ve been closely involved with the Trinity College cast (see previous posts here and here). Again, it’s great to see a more unusual taxon reproduced in toy form and I’ll review this figure properly soon.

That’s it for new plesiosaur figures for 2011, but who knows what the future might bring…

During the past decade several dramatically named giant pliosaurs have hit the mainstream media, many claiming to be the biggest yet discovered. But only a trickle of peer-reviewed literature has been published to accompany these news stories. The lack of published data makes it really difficult to sift the facts from the fiction, and it’s easy to get the different stories muddled up, especially in the case of two identically sized congeneric pliosaur specimens from Svalbard: ‘The Monster’ and ‘Predator X’. So in an attempt to iron out the details and assess what we really know about all these specimens, here’s a short summary of the main players.

The Monster of Aramberri
Hit the mainstream media: 2002.
Estimated length in media: 18 m.
Conservative estimated length 15 m.
Material: Partial vertebral column, proximal end of a femur, part of the pelvic girdle, and cranial fragments. The fragment of rostrum collected in 1985 is now lost.
Where: Aramberri, Mexico.
Excavation: The original excavation in 1985 yielded a partial rostrum and vertebral column. The excavation site was reidentified in 2001 and additional material was collected during 2001 and 2002.
Peer-reviewed scientific references: Buchy et al. (2003).
Notes: The material was collected over a period of several years, but the discovery only hit the mainstream media in 2002 when more substantial pieces of the skeleton were discovered. An excellent account of the ‘Monster of Aramberri’ is given here by Richard Forrest. Buchy et al. (2003) described UANL-FCT-R2, the partial vertebral column discovered in 1985 [pictured below], but the majority of the skeleton has not been described and is in the process of being prepared. I’ve confirmed with Marie-Celine that the vertebrae described in 2003 are part of the ‘Monster of Aramberri’, but it is worth noting that the 2003 paper doesn’t explicitly mention ‘The Monster of Aramberri’ by name. Originally referred to Liopleurodon, it isn’t considered so any more (Buchy & Frey, 2003).

Part of a figure from Buchy et al. (2003) showing some of the vertebrae and girdle elements of 'The Monster of Aramberri' of the

The Monster
Hit the mainstream media: October 2006
Estimated length in media: 15 metres
Conservative estimated length: 13-15 m
Material: anterior part of rostrum, two cervical and numerous dorsal vertebrae, a nearly complete coracoid and right forelimb, and several dorsal ribs and gastralia.
Where: Svalbard, Norway.
Excavation: Discovered in 2006 and excavated in 2007.
Peer-reviewed scientific literature: none.
Notes: ‘The Monster’, not to be confused with ‘The Monster of Aramberri’, was the first pliosaur from Svalbard to be excavated and the first to make the news. A second giant pliosaur (‘Predator X’, see below) was discovered at the same time, but was excavated the following season. Richard Forrest’s 2008 article on the plesiosaurs from svalbard provides a thorough discussion, including comments on ‘The Monster’, but it was written before the second pliosaur hit the mainstream media.

Partial forelimb of 'The Monster'

Predator X
Hit the mainstream media: March 2009
Estimated length in media: 15 m
Conservative estimated length: 13-15 m
Material: Partial skeleton including posterior skull region and anterior cervical vertebrae.
Where: Svalbard, Norway.
Excavation: Discovered in 2006 and excavated in 2008.
Peer-reviewed scientific literature: none.
Notes. The fossil material attributed to this pliosaur was first mentioned in stories covering “The Monster” in 2008, but the name ‘Predator X’ was coined after the specimen was excavated and it hit the media in 2009. According to an SVP poster by Knutsen et al. (2009) both ‘The Monster’ and ‘Predator X’ belong to the same taxon – they are congeneric and they are closest in their anatomy to Pliosaurus. They are both estimated to be the same size, and they are also both from the same geological formation, so with all these similarities it’s easy to confuse the two. ‘Predator X’ inspired the cover story for the 31 October 2009 issue of New Scientist, and was the main subject of a recent History Channel documentary of the same name, which also featured another giant pliosaur – the Weymouth Bay pliosaur. ‘Predator X’ will also appear in the BBC’s upcoming series Planet Dinosaur. Despite its widespread presence in the news and on TV, I was unable to find a suiatable photograph of the actual material.

The Weymouth Bay pliosaur
Hit the mainstream media: October 2009
Estimated length in the media: 16 m
Conservative estimated length: 12 m.
Material: skull and mandible (missing the tip of the manibular symphysis).
Where: Weymouth Bay, Dorset, UK.
Excavation: Discovered in pieces over a period of time – specific details unclear. The specimen was purchased by Dorset County Museum in Dorchester.
Peer-reviewed scientific literature: none.
Notes: There is an excellent account of the Weymouth Bay pliosaur here by Richard Forrest. The skull as preserved is 2.1m long.

The Weymouth Bay pliosaur and Richard Forrest

So there we have it, four mega-pliosaurs making big news in the space of a decade. All of them have conservative and realistic length estimates around the 15m mark, with the Weymouth Bay pliosaur possibly slightly smaller and ‘The Monster of Aramberri’ possibly slightly larger. But all the estimates are way too wooly to take seriously just yet. So all these monsters will remain jostling for top spot until the scientific papers are published, and until we have a better understanding of pliosaurid proportions.

There are or course plenty of other giant pliosaurs, which frequently pop up in discussions too, including additional real contenders for ‘biggest pliosaur ever!’. While I do plan to write more on giant pliosaurs in the future, I’ve stuck to the ones in the mainstream media for now. You might have noticed that Liopleurodon was conspicuously omitted from this post. Well, although it is entirely relevant to the present topic, it hasn’t been in the news recently so I decided to leave the magical Liopleurodon alone this time around. It will be nice to write about a pliosaur with an actual scientific name for a change, even if that’s opening a can of worms in itself!

References

Buchy, M.-C. & Frey, E. 2003. Was it really eating granite? We’re searching hard: history of the Monster
of Aramberri (and stories about it). First meeting of the EAVP – abstracts, 39.

Buchy M.-C., Frey E., Stinnesbeck, W. ; López-Oliva J.G. 2003. First occurrence of a gigantic pliosaurid plesiosaur in the Late Jurassic (Kimmeridgian) of Mexico. Bulletin de Societe géologique de France, 174, 271-278.

Knutsen, E., Druckenmiller, P., Hurum, J., Nakrem, H. 2009. Preliminary account of new Late Jurassic pliosaurid material from Svalbard, Norway. Journal of Vertebrate Paleontology, 128A.

Noè, L. F., Smith, D. T. J. & Walton, D. I. 2004. A new species of Kimmeridgian pliosaur (Reptilia; Sauropterygia) and its bearing on the nomenclature of Liopleurodon macromerus. Proceedings of the Geologists’ Association 115, 13-24.

I previously reported (see here and here) on the plesiosauroid skeleton discovered in 2007 in Kreis Hoxter, near Bielefeld, Northern Germany. The specimen was excavated from the Pliensbachian (Lower Jurassic) age strata in ten large blocks by the LWL-Museum für Naturkunde, Münsterand. A major proportion of the fossil has now been prepared by Manfred Schlösser: the skeleton is almost complete and quite spectacular.

'Kreis Hoxter plesiosaur' on display in the Köln Museum. Looks like the tail is complete. (Photo by Sönke Simonsen)

In 2010 the ‘Kreis Hoxter plesiosaur’ was displayed in the Römisch Germanisches exhibition in the Köln Museum (The photos here show the specimen as displayed) and in April 2011 the specimen will comprise part of the new archaeological and palaeontological exhibition “Fundgeschichten” in the Westfälische Museum für Archäologie in Herne. German press reports early in 2011 (see here for example) announced that the ‘Kreis Hoxter plesiosaur’ represents a new taxon and a description is currently in press.

'Kreis Hoxter plesiosaur' in the Köln Museum, showing detail of the cervical vertebrae (Photo by Sönke Simonsen)

The 'Kreis Hoxter plesiosaur' in the Köln Museum showing detail of the pelvic region (Photo by Sönke Simonsen)

Thanks to Sönke Simonsen for information and photographs.

An exciting new paper published this week in the journal Science (Vol. 333, p.870-873) provides the first direct evidence for live birth in plesiosaurs, and may have implications for plesiosaur behaviour (O’Keefe & Chiappe, 2011).

The plesiosaur Polycotylus giving birth to a single large baby. Based on new fossil evidence. Image by S. Abramowicz/NHM

Whether plesiosaurs laid eggs or gave birth to live young has been a topic of speculation for nearly 200 years. They have sometimes been portrayed crawling out of the water to lay eggs in the manner of sea turtles, and while palaeontologists have long suspected that plesiosaur anatomy is incompatible with movement on land, empirical evidence either way has been lacking.

The new evidence comes in the form of a fossil plesiosaur skeleton with a fetus preserved in the body cavity. Both individuals have diagnostic characteristics indicating they are the same species, the small individual displays embryonic features and is in the correct position to be a fetus, and there are no signs of it being eaten (bite marks or acid wear). These numerous lines of evidence confirm that this fossil represents a mother and her unborn fetus. This demonstrates that plesiosaurs did not lay eggs and were therefore able to lose their ties with land and spend their entire lives in the ocean.

The evolution of live birth in plesiosaurs would have allowed them to lose all ties with land. Depictions like the one above of a Jurassic plesiosaur (Hydrorion) are therefore highly unlikely. Painting by Burian.

The newly described fossil plesiosaur is a polycotylid (Polycotylus), one of the last types of plesiosaurs to evolve. It was discovered in Late Cretaceous rocks in Kansas, USA. Polycotylids were highly derived plesiosaurs with torpedo-shaped body outlines and wing-like flippers, a relatively short neck (as far as plesiosaurs go) and a very short tail. They were almost penguin-like in general appearance and also similar to penguins, they would have been fast and agile swimmers.

An unusual aspect of this fossil is the size of the fetus. Most viviparous reptiles give birth to a brood of several small individuals. In contrast, this new fossil shows that at least some plesiosaurs gave birth to a single very large individual, much like whales do today. Many other marine reptiles including ichthyosaurs and mosasaurs gave birth to live young, but this study suggests that plesiosaurs differed in that they invested energy and time into a single individual. This sort of reproductive strategy is often associated with gregarious behaviour and parental care, so the authors of the paper suggest that maybe plesiosaurs were excellent parents too. This hypothesis is fascinating although it would be quite unusual for reptiles.

Illustration showing the relative size of a mother Polycotylus and newborn baby. From O'Keefe & Chiappe, 2011)

Fossils of basal sauropterygians (pachypleurosaurs and nothosaurs), close relatives of plesiosaurs, also show that they gave birth to broods of several small live babies, so it is unclear when the evolutionary shift in reproductive strategy occurred in the sauropterygian lineage. It is certainly possible that the first plesiosaurs were more like their ancestors in terms of reproductive behavior. More fossils will ultimately be required to fill in the bigger picture, but for now, it is wonderful to be able to say with certainly that plesiosaurs gave birth to live young.

Reference

O’Keefe, F. R. & Chiappe, L.M. 2011. Viviparity and K-selected life history in a Mesozoic marine reptile. Science, 333, 870-873.

Astute viewers of BBC’s plesiosaur-fest on Planet Dinosaur this week may have spotted my name dash across the screen at the end credits. ‘Fight for Life’, the fourth in the series, was the first episode, and so far as I’m aware only episode, to plunge us into the Mesozoic oceans and introduce us to some marine life. I’ll obviously skip the dinosaurs and concentrate just on the plesiosaurs.

Having seen the earliest designs of the marine reptiles for this episode, and later the first test animations, the show might have been heading for a disaster. You can thank me now, if you wish, for helping to purge swan-necks from the show and for banishing bodily undulations from the plesiosaurs’ locomotory repertoire. Looking back at the huge gulf in accuracy between the early designs I saw and the finished renderings helps me to put them into perspective, and so I look upon the anatomical issues that remain with some relief in the knowledge that they could have been so much worse. But I would certainly tweak aspects of the anatomy and movement if I had the chance. Of course, budget and deadlines all played a factor and limited the amount of back and forth possible in the design process. And it also doesn’t help that so little is actually known about the stars of the show, both Kimmerosaurus and Predator X. The designers depend on existing reconstructions and restorations for visual guidance and this is often lacking.

The cryptoclidid plesiosaur Kimmerosaurus is closely related to Cryptoclidus. It was named in 1981 on the basis of an isolated skull (Brown, 1981). Some referred material, including some anterior cervical vertebrae, was later identified and subsequent comparison of these vertebrae with those of  Colymbosaurus, a genus known inconveniently from everything but a head, led Brown et al. (1986) to suggest both genera belonged to the same taxon. Whether congeneric or not, the similarities in the overlapping anatomy are close enough that skeletal data from Colymbosaurus was used as a basis for filling in the gaps in our knowledge of the postcranium of Kimmerosaurus in Planet Dinosaur. Another problem though, is that Colymbosaurus is a bit of a prickly taxon itself, but I won’t confuse matters any further. Taxonomy aside, we know that at least one moderately large (up to around 6m) long-necked plesiosaur skulked around in the Late Jurassic. Plesiosaurs from the Tithonian of Svalbard have been tentatively referred to Kimmerosaurus.

Kimmerosaurus gets a close up in Planet Dinosaur. Copyright BBC.

Predator X is a pliosaur with more media hype than it probably deserves, and a ridiculous name betraying how little we actually know about it. A foray into the twitterverse provided some insightful public reactions to the name that follwed the program, some of which I’ll share here:

@furiousgerbil said:
Right. There’s a dinosaur called ‘Predator X’ that’s a rubbish name. It should be called a Furiousaurus. I’ll write a letter. To someone.

@chrismeredith quipped:
I would enjoy Predator X more, but I haven’t seen Predators IV-IX yet.

@backwards7 joked:
Naming a dinosaur ‘Predator X’ makes it sound like the anonymous defendant in a sexual assault trial.

And @JohnLoony was justified to ask the legitimate question:
“Planet Dinosaur” on BBC1 featured a big marine pliosaur called “Predator X”. Why doesn’t it have a proper Latin classification name?!??

Firstly, it’s not a dinosaur, this should really have been made clearer in the program. Secondly, there is a reason why it doesn’t have a proper scientific binomial name: it hasn’t been described yet. ‘Predator X’ is really just the name for the individual animal and isn’t intended to be a stand in name for the taxon, although I think that’s how it was received by many viewers. Such is the power of media hype. I’ve skimmed over the history of Pred X in a previous article where I’ve explained that preliminary research by Knutsen et al. (2009) allies Predator X with Pliosaurus. I can’t bring myself to constantly refer to this animal as Pred X every time, so I’ll tend to go with the term pliosaur from now on instead…

Predator X swims overhead in Planet Dinosaur. Copyright BBC.

So, let’s review what we saw. Overall I was quite pleased with the appearance of the pliosaur, which was based on reconstructions of Pliosaurus. But there are problems. The dentition is way off and altogether rather too generic, with the diagnostic large caniniform teeth omitted completely. I was never consulted about the teeth of the pliosaur so I dodge all responsibility here, but I do know the animators had issues with the teeth of Kimmerosaurus too, its mouth wouldn’t shut unless they shrunk and tweaked the angle of the teeth a bit. In the case of both Kimmerosaurus and the pliosaur, the modelers had wrongly endowed them with a slight overbite, so the tooth rows don’t quite line up as they would have in life – no wonder they couldn’t get the teeth to interlock. The teeth were added at a later stage in the design procedure, after the overall body shape had been finalised, so it was too late to go back. As a workaround, they angled the teeth in the mandible more horizontally and shrunk them a bit. Dodgy stuff. The puffy eyelids in the pliosaur seemed a bit unnecessary and I’d have preferred more musculature at the rear of the jawline, but overall the head is pretty good in my opinion.

I thought the head of Kimmerosaurus, with its nice long tooth rows of many tiny teeth, was rather good too. I spotted the far too deeply concave temporal fenestrae quite early on in the design process and despite my concerns (they were supposed to be filled out later on) they still managed to find their way into the finished renderings. The dinosaurs in the series have also suffered the same fate. At least the eyes weren’t placed in the temporal fenestrae in Kimmerosaurus as has occurred in other plesiosaur restorations.

The bodies of both animals are also generally good, with satisfyingly streamlined outlines and beefy musculature around the base of the limbs, fitting for animals that propel themselves through the water by flipper power. The slightly flattened tip of the tail in the pliosaur was a compromise between a fully developed tail fin, a feature I and others suspect many plesiosaurs had, and no tail fin at all. I liked it. I liked the grizzled appearance of the pliosaur’s skin, but while I was pleased to see the end of the obligatory black and white pattern so often attributed to large pliosaurs (post WWD Liopleurodon), I was a bit disappointed that every single plesiosaur was basically grey. I’d have loved a few greens, or at least some differentiation between the predator and prey. Also, despite my suggestion, no parasites or patholoies to be seen on any of the beasties, which I thought was a lost opportunity.

Well, I think I’ve gone on far enough for now so I’ll leave discussion of the behaviour, animation and range of motion for part 2. Suffice to say there are issues. Comparisons with the WWD episode ‘Cruel Sea’ are also justified and I may head into such territory on a later occasion too.

References

Brown, D. S. 1981. The English Upper Jurassic Plesiosauroidea (Reptilia) and a review of the phylogeny and classification of the Plesiosauria. Bulletin of the British Museum (Natural History): Geology, 35, 253-347.

Brown, D. S., Milner, A. C., and Taylor, M. A. 1986. New material of the plesiosaur Kimmerosaurus langhami Brown from the Kimmeridge Clay of Dorset. Bulletin of the British Museum (Natural History), Geology, 40, 225-234.

Knutsen, E., Druckenmiller, P., Hurum, J., Nakrem, H. 2009. Preliminary account of new Late Jurassic pliosaurid material from Svalbard, Norway. Journal of Vertebrate Paleontology, 128A.

So, time for more Planet Dinosaur plesiosaurs… In part 1 of we familiarised ourselves with the taxonomy and appearance of the plesiosaurian stars of the fourth episode of the BBC’s Planet Dinosaur, ‘Fight for Life’. Now we’re all set up to pick apart, with ruthless abandon, the animators’ painstaking efforts to bring these animals to life.

Predator X. We're going to need a bigger blog. Copyright BBC.

Plesiosaur swimming is an active area of research and frankly we don’t know exactly how they swam. There are some fundamental uncertainties in our understanding of plesiosaur locomotion, in particular, how did the four limbs move relative to each other? Sure, we might also be off in our estimations of dinosaur gaits too, but at least we have the footprint evidence to understand the basics. For example, theropod dinosaurs like Allosaurus, which also appeared in this episode, put one foot in front of the other. Yet the animators still didn’t quite manage to capture this satisfactorily as to my eye the walk cycles in the Planet Dinosaur dinos are pretty wooden. So, with this in mind, what chance did the plesiosaurs have?

Well, I’m probably overstating the point. It is true that we don’t know exactly how plesisoaurs swam, but we do have a good understanding of the limb strokes in general, and we know how they didn’t swim. So let’s start there. Derived aquatic animals generally swim either by undulating their body (e.g. crocs, dolphins etc.) or by keeping their body sturdy and using their limbs (e.g. turtles, penguins). Plesiosaurs are in the latter category and their skeleton is constructed accordingly to resist flexibility. They have tightly articulating dorsal vertebrae, robust ribs, and a strong rigid ventral skeleton consisting of flat plate-like girdles, bridged by a strong mesh of gastralia (belly ribs).

To my distress, some early movement cycles of the Kimmerosaurus included not only a limb-based phase, but also a wriggling  phase with long lateral undulations of the whole body, with the flippers pulled in flush to the flanks. In this regard, the Planet Dinosaur plesiosaurs originally wanted to have their cake and eat it. Thankfully these side-to-side wiggling phases, and also an up-down wiggling phase, didn’t appear in the final show. However, there is still a little too much dorso-ventral flexibility in the plesiosaur bodies on occasion. The Kimmerosaurus sometimes appear rather too bendy, and in one scene the pliosaur pretty much breaks its own spine, but I was pleased to see these deviations kept to a minimum.

It is generally agreed that the plesiosaur flipper stoke was essentially a modified form of underwater flying with a major up-down component and minor back-forth component. They were not used to row and it is unlikely that the flippers could be pulled back to be flush with the flanks of the body, even though they do this every now and again in the show. The limb-stroke of the forelimbs also looks a bit off at times in Planet Dinosaur. It is my understanding that the digital models are rigged with approximate points of flexibility – they don’t have anatomically correct skeletal anatomy inside – so it is only to be expected that the points of joints and range of motion may not always be spot on. It’s also worth bearing in mind than animators are not biologists, yet they’re ultimately responsible for the construction of biological critters.

When I saw the trailer for Planet Dinosaur I noticed the flippers in the pliosaur being pulled back almost flush with the body and feared for the worst. This happens in the scene when the pliosaur comes to blows with the Kimmerosaurus. But this was a one off and for the most part the pliosaur is cruising around with healthy deep limb strokes. Plesiosaurs may have changed their gait depending on the the velocity and maneuverability they wished to achieve, so it is also reasonable to suppose that all four limbs sometimes moved in unison for a burst of speed, as also depicted in the show. Overall, I thought the Kimmerosaurus‘ elegant prancing and dancing, twisting and turning, was wondrous. It would be unfair, and perhaps premature given our current state of understanding, to pick on it too much.

I had some problems with the interactions between the animals and their underwater environment, the water resistance wasn’t always convincing. At times the plesiosaurs seemed to move via some sort of invisible jet propulsion. Either that, or the momentum being generated from the limb stokes was overestimated. This might be put down to limitations in the technology, and I suppose there is a certain amount of intuition required for perfecting these details. similar explanation could also be invoked to explain why some of the dinosaur walk cycles in the series don’t always cut it when it comes to mass and momentum.

A quick note on that characteristic feature of the plesiosaur, the long neck, which was correctly restored as a relatively inflexible structure. Not a swan-like pose in sight, and no graceful necks arching out of the water. Other recent documentaries (e.g. Sea Rex 3D) just couldn’t resist including such outdated but iconic imagery, presumably against better advice. The evidence for plesiosaur feeding habits from the gutter-like trace fossils, or Lebensspuren (for that it their proper name), was discussed by Darren Naish on the old version of his Tetrapod Zoology site. These structures might have been produced by plesiosaurs, they might not, but it is a reasonable suggestion that fits with other evidence from stomach contents (McHenry et al., 2005).

Kimmerosaurus - The Jurassic vaccume cleaner. Copyright BBC.

On several occasions in the program the plesiosaurs break the surface, where, dowsed in harsh sunlight, I’d be hard pushed to tell whether the splashes are CGI or real (if I didn’t already know). These scenes were really excellently excecuted. The pliosaur comes up for air at one point and snorts out a powerful jet of water spray from its external nostrils. It isn’t certain that plesiosaurs breathed through their tiny external nostrils, especially if they employed the method of underwater olfaction explained in the show (these plesiosaurs want to have their cake and eat it again!), but, well, why not, it looked nice didn’t it!

The scientific exposition sections included some dodgy versions of my Rhomaleosaurus reconstruction as a stand in for Predator X, which was therefore anatomically incorrect for a pliosaurid. I believe that the Kimmerosaurus illustration was also based on my Rhomaleosaurus reconstruction. The tooth mark evidence in the skull of a plesiosaur comes from an elasmosaurid specimen formerly referred to the nomen dubium ‘Woolungasaurus‘, and now known as Eromangasaurus australis (following some confusion resulting from two researchers accidentally stepping on each others toes a little and publishing reviews of the material almost simultaneously – the specimen had a short stint as Tuarangisaurus australis and Eromangasaurus carinognathus) (Kear, 2007). Anyway, it certainly isn’t Plesiosaurus as the reconstruction was mysteriously labelled in the show. The interpretation of the bite marks is pretty speculative as who knows for sure the position of the the animal in the water column? But pliosaurs sometimes ate long-necked plesiosaurs, that is certain.

A hungry Predator X wrestles with a sand bank in search for tasty Kimmero-morsels. Copyright BBC.

As scientists, palaeontologists have the luxury of not having to commit to any single hypothesis. We can say without shame that we don’t know, at least not with certainty, how plesiosaurs hunted, how they breathed, how they swam. We can interpret evidence tentatively and you’ll have noticed the frequent use of non-commital language in this review such as ‘probably’ and ‘unlikely’. But this doesn’t help artists, script writers or animators who, charged with the task of restoring these long-dead beasties, are forced to plump for one option of the other (under the format used by Planet Dinosaur at least). With all the pitfalls presented to them along the way, I think the Planet Dinosaur team did a sterling job bringing Predator X and Kimmerosaurus back to life. And no, I’m not being apologetic, or sympathetic, just because I was involved. I’m really enjoying this series and look forward to the other episodes.

References

Kear, B. 2007. Taxonomic clarification of the Australian elasmosaurid genus Eromangasaurus, with reference to other austral elasmosaur taxa. Journal of Vertebrate Palaeontology, 27, 241-246.

McHenry, C., Cook, A., and Wroe, S. 2005. Bottom feeding plesiosaurs. Science, 310, 75.

Most museum collections contain hidden treasures, but the Honington plesiosaur in the Warwickshire Museum is one treasure, I’m pleased to say, that is no longer hidden.

The Honington plesiosaur being laid out in preparation for display. The position of some of the bones is tentative. Photo by Warwickshire Museum, used with permission.

I first came across the Honington plesiosaur while working in the geological collection  of the Warwickshire Museum under the supervision of Jon Radley, the curator of natural sciences. While in the stores, my beady little eyes couldn’t help but spot the neatly printed name, ‘Plesiosaurus rugosus’, on an unopened dusty box. Upon further inspection we discovered, to our astonishment, an almost complete long-necked plesiosaur skeleton. I took the time to lay out the remains and after a little digging through documentation, we were able to confirm that the specimen originated from Honington, near Shipston-on-Stour, in Southern Warwickshire. The fossil is also well-constrained stratigraphically, which is quite rare for historical specimens of Lower Jurassic plesiosaurs.

Here I am, laying out the Honington plesiosaur. Photo by Warwickshire Museum, used with permission.

The specimen consists of an almost complete postcranial skeleton, but unfortunately lacks any trace of the skull, as is often the case in long-necked plesiosaurs. This is partly because the small skull in plesiosauroids is delicately constructed and prone to damage. Despite the missing cranium, the specimen is noteworthy because it is preserved in three dimensions and is free from matrix. This means it is possible to view and study the bones from all directions and gather proportional data.

The Honington plesiosaur exhibited in the Warwickshire museum. The bones are raised on two levels to add a sense of three-dimensionality. Notice the replica skull. Photo by Adam S. Smith, taken October 2010.

Jon and I are in the process of writing up a description of the specimen and assessing its identity and evolutionary significance. In the meantime,  the Honington plesiosaur has quite rightly wriggled its way out of storage and onto public display. It’s now exhibited in a beautiful case as part of a recently renovated gallery. I was happy to be able to assist with the Honington display and provided a life-restoration of the animal as a graphic to accompany the new display. A resin replica of a skull representing Plesiosaurus is doing a fine job as a replacement for the missing cranium. The fossil also makes a fitting counterpart to another spectacular marine reptile on show in the gallery, the Wilmcote plesiosaur – a beast for a future blog entry perhaps? So if you’re in the region, do drop in!

There was a time when I’d leap into tippy-tappy action at the first sniff of a newly named plesiosaur. Unfortunately, I haven’t been keeping Plesiosaur Bites up to date and a few new taxa have passed me by. Of course, when I say “a few”, what I really mean is we are swamped by the things. Little wonder I haven’t been able to keep up.

A few years ago I plotted a graph in my PhD thesis (Smith, 2007, Figure 2.2.) to show the number of valid plesiosaur species and genera named in successive 20-year time intervals since 1821 (when the first plesiosaur was named [Plesiosaurus]). The data ended in 2007, the year I submitted my thesis, but showed that new taxa were being erected at a relatively steady rate throughout the 19th and 20th century (Figure 1). The rate started to pick up during the 1990s and I extrapolated the data into 2008-2020 based on the first seven years of the 21st century. I predicted 30 new genera in the period 2001-2020, which would represent a huge post-2001 leap in the number of new valid plesiosaurs. Well, so much for my crude calculations. It’s only 2012 and my ‘huge’ prediction has already been surpassed.

Figure 1. Tally of the number of new plesiosaur taxa per 20-year interval (from Smith, 2007, Y-axis adjusted for direct comparison with Figure 2 below). 2001-2020 predicted based on 2001-2007 data.

Earlier this month I co-authored a poster at SVP 2012 describing a new pliosaur from the Sinemurian of Lyme Regis (Smith and Araújo, 2012). I was unable to attend the conference in person so my collaborator and friend Ricardo Araujo was on hand to present our preliminary findings.

Ricardo Araújo stands proudly next to our poster at SVP 2012. Ricardo is conducting a PhD on plesiosaurs at the Southern Methodist University, Texas.

The spectacular specimen was discovered at Black Ven, Lyme Regis, and was acquired by the Niedersächsisches Landesmuseum, Hanover, where it was expertly prepared in the 1990s by their preparator, Elija Widman. The fossil consists of an almost complete skull and vertebral column.

The Lyme Regis pliosaur as articulated

As explained in our poster, the fossil represents a new taxon that is both stratigraphically and morphologically intermediate between known Hettangian and Toarcian rhomaleosaurid pliosaurs. Which makes perfect sense. A legible (just about) jpg version of the poster is available here or by clicking the small version below, and a PDF of the abstract is available here. This is very much a work in progress though and more of a sneak preview than a final word. We have a paper in prep which will provide a more detailed description of the specimen.

Poster for SVP 2012

References
Smith, A.S. and Araújo, R. 2012. A new rhomaleosaurid pliosaur from the Sinemurian (Lower Jurassic) of Lyme Regis, UK. Program and abstracts, 72nd Annual Meeting of the Society of Vertebrate Paleontology, Supplement to the online Journal of Vertebrate Paleontology, 74. [PDF here]

[Incidentally, how does one cite an SVP abstract correctly these days?]

I’ve been rather quiet again recently, however, as coauthor of an article just published in PLOS ONE, I’ve good reason to come out of my shell today. The new paper describes and names the Weymouth Bay Pliosaur, a spectacular almost complete skull over 2m long from. As discussed in the open access paper (do take a look), the specimen is sufficiently different from all other pliosaurs to warrant a scientific name of its own, Pliosaurus kevani.

Pliosaurus kevani was named in honour of Kevan Sheehan, the Osmington Mills café owner who collected most of the skull, piece by piece, over a period of eight years during daily walks along the foreshore. Kevan collected chunks up to 60 kg in mass as they weathered out from the Jurassic aged Kimmeridge Clay Formation sea-cliff. The specimen was purchased with funding secured by Dorset County Council’s museum service from the Heritage Lottery Fund Collecting Cultures programme and Dorset and Devon county councils. It was prepared between 2010 and 2011 by Scott Moore-Fay and went on public display in Dorchester County Museum in July 2011.

Richard Forrest, who was involved with the project from the beginning, first had the idea of putting together a ‘dream team’ of British plesiosaur specialists to study and describe the skull. This is the first collaboration of its kind among plesiosaur researchers (as far as I know), and I feel lucky to have had the opportunity to contribute to it under the driving force of our lead author, Roger Benson.

Roger Benson (left) and Richard Forrest (right) collecting data from the Weymouth Bay Pliosaur – Pliosaurus kevani

The massive skull has a long snout, circular orbits, huge temporal openings for the jaw musculature, and a deep mandible. Large portions of the skull have been crushed flat during fossilisation, so one of my tasks was to reconstruct the skull to show how it might have appeared before it was flattened. After several versions and much input from Mark Evans, I’m pleased with how it turned out, and I think we have a pretty accurate reconstruction of Pliosaurus. On the basis of this reconstruction I’ve also had a go at restoring the life appearance of the head of P. kevani in profile. Despite its large size and massive teeth, the head is rather gracile.

Pliosaurus belongs to a group of plesiosaurians known as thalassophonean pliosaurs. If you haven’t heard of them before, that’s because the name Thalassophonea, or “sea slayers”, was proposed just this year (Benson & Druckenmiller, 2013) for a natural group of derived giant pliosaurids including Pliosaurus, Liopleurodon, and Kronosaurus. Thalassophoneans were macropredators, that is, giant predators doing the sort of dirty work in the Middle-Late Jurassic and Cretaceous that rhomaleosaurids had done in the Early Jurassic. The paper also discusses the evolution of pliosaurids. The earliest thalattophoneans have a long mandibular symphysis, but in later member it becomes shorter. This trend is related to a shift in the dietary habits of pliosaurs from primarily fish-eaters to macropredators. In conjunction with this trend, we demonstrate that pliosaurids tend to follow Cope’s Rule – they get larger throughout their evolutionary history.

We also name two other new species of Pliosaurus in the paper, P. westburyensis and P. carpenteri, based on material in the Bristol Museum & Art Gallery from Westbury, Wiltshire. Again, there are aspects of the morphology in these specimens that distinguish them from one another, but don’t justify new genus names. So, add these new species to the existing list of valid Pliosaurus species (P. funkei, also known as Predator X, P. brachydeirus, P. rossicus, there might be one or two more, pending thorough description of the material) and we find ourselves with a rather large number of species within a single genus (although some invalid species of Pliosaurus are sunk too). Future research might show greater generic diversity among these species, but that’s really dependent on the discovery of more satisfactory fossil material.

The Golden Trilobite is awarded annually by the Palaeontological Association to “high quality amateur and institutional websites that promote the charitable aims of the Association”. I’ve no idea who nominated my website this year, but my thanks go to whoever raised it to the attention of the the PalAss Council, because it was a welcome surprise to learn that the Plesiosaur Directory was awarded the 2013 Golden Trilobite.

I’m obviously delighted and honoured for The Plesiosaur Directory to win this award, and I thank PalAss for  recognising the site in this way. The Plesiosaur Directory started life as a small Geocities hosted site way back in June 2001, under the full title of “THE PLESIOSAUR DIRECTORY: A REVIEW OF THE SAUROPTERYGIA”. The site transferred to its own domain in March 2006 (plesiosauria.com), and remained in a basic html format until 2011, when I finally learned a bit of php and launched a new version of the site. This has been steep learning curve for someone with no training, and things are only going to get more difficult, as my next task is to convert The Plesiosaur Directory to a database driven site (at the moment only the plesiosaur bites blog is database driven), which will make it far easier to update and manage. The site has received other accolades in the past, such as when the journal ‘Science’ featured it in the “best of the Web in Science” (2006, Vol 313, Issue 5791, P.1211), so I suppose this means I must be doing something right.

However, these accolades remind me that there’s so much work left to do. Frankly, I’m not satisfied with the site as it stands, and I’m fully aware there are a great many genera missing from the directory, and numerous pages are rapidly becoming out of date as palaeontology marches on relentlessly. Some of the content hasn’t been updated since 2001, and was therefore written by a 20-year-old student version of myself. Back then, I could barely string together a coherent sentence. There are all sorts of reasons why I’ve let things slowly slip a little. However, this award will spur me on to upgrade the code, fill in those missing gaps, update the various galleries and pages, and write blog articles more frequently. There’s certainly no shortage of topics to cover.

The Plesiosaur Directory isn’t the only site dedicated to plesiosaurs. There are, in my opinion, other sites equally deserved of such an award. The Plesiosaur Site (plesiosaur.com), in particular, run by Richard Forrest, contains a wealth of data on plesiosaurs. Especially useful is the database containing information on plesiosaurian collections, distribution, taxonomy, and references. A major inspiration. Richard also hosted The Marine Reptiles Forum on plesiosaur.com until it was hacked earlier this year. We hope to get that back up and running soon.

For more information on the Golden Trilobite, including previous winners, see here. 

The marine reptiles forum, which was unfortunately hacked last year (2013) and has been offline for several months since, is now back up and running. Richard Forrest was able to salvage all the old posts and user information, and has restored the forum at a dedicated new domain: marinereptiles.org. The forum is home to an open community of fossil marine reptile researchers and enthusiasts, and is an  excellent place to discuss all manner of topics related to prehistoric marine reptiles. The site is run by Richard Forrest (plesiosaur.com), Mike Everhart (oceansofkansas.com), and myself, so we’ll do our best to minimise spam and approve genuine new members without too much delay. Registration is now open so see you there!

In Plesiosaur Peril, author Daniel Loxton plunges us into the Jurassic ocean, to recount a day in the life of a baby Cryptoclidus. The book is the third in Loxton’s ‘Tales of Prehistoric Life’ series, which includes the stories Ankylosaur Attack and Pterosaur Troubles.

In this short children’s story we follow a juvenile Cryptoclidus and the rest of her pod as she goes about her daily chores. She seeks some gastroliths, gulps salty sea air, hunts for food, and eventually follows some prey that leads her astray. Of course, this isn’t an ocean paradise free of danger. The villain of the tale is Liopleurodon and our heroine soon finds herself in a perilous situation – you’ll have to get your own copy to discover if curiosity killed the Cryptoclidus!

The book is aimed at children aged 8–12 so the paragraphs are short, snappy, and easy to read. There’s a healthy balance between text and imagery, and the visuals, also by Daniel Loxton (with Jim W.W. Smith), illustrate the story beautifully. They consist of a combination of real world photography and computer-generated digital art, which blend almost seamlessly.

The fossil remains of Cryptoclidus and Liopleurodon are known from the Oxford Clay Formation of Europe (165 million years ago), so the two species certainly lived alongside each other. It is apparent from the accurate appearance of the plesiosaurs that they were thoroughly researched. Darren Naish is credited in the acknowledgements and presumably takes credit here. The proportions and anatomy are just right, and the same is true for the other prehistoric creatures that show up throughout the story: ichthyosaurs, ammonites, belemnites; all beautifully rendered and well-researched. They are the best I’ve seen in any book of this kind.

Quite sensibly, the story itself isn’t bogged down in facts and figures, however, the last page of the book provides some insights into both plesiosaur species for those wishing to dig a little deeper. In particular, this section outlines some of the evidence for the events recounted in the story. Darren Naish has also posted a detailed online article on his Tetrapod Zoology blog, covering some of the behaviour depicted in the book, beating me to it by several weeks! So, instead of covering the same ground, I direct you there.

In conclusion this is a lovely and visually striking book that makes the perfect bedtime story for any child with (or without, for that matter) an interest in prehistoric life. I look forward to seeing what the future may hold for the ‘Tales of Prehistoric Life’ series.

Plesiosaur Peril is available from Amazon.com here and Amazon.co.uk here,  and also from Amazon.com via the Plesio-store here.

“I’ll tell you a story — and some of it’s true –
that explores and explains
what the Bone-Hunters do.”

You’re probably already familiar with the Bone Wars, or the Great Dinosaur Rush, but you won’t have seen this real-life rivalry between two prolific 19th century palaeontologists portrayed quite like this before. Based loosely on historical events, this fanciful version of proceedings, written by Ted Enik, sees both parties in the ‘war’ inventing dinosaur species by the dozen. So, how come I’m reviewing it here? Well, the link may be tenuous, but a plesiosaur makes an appearance at the beginning and end of the book, and that’s all I required to give in to curiosity…

The book opens with a factual introduction that sets the scene, after which, the story takes the form of an engaging Dr Seuss-like poem. The rhyming, rhythmical text is snappy and funny, and at 33 pages long this is a sizeable volume. The story is supplemented on every page with charming stylistic artwork by G.F. Newland. For example, in a preface to the book, we see our plesiosaur restored, and in another early scene, we see our plesiosaur skeleton being unearthed. There’s a passing resemblance of the two main protagonists to their real-world counterparts, O.C. March and E.D Cope, which is surely no coincidence.

Enik states up front that this is a whimsical “take” on events, though it isn’t stated explicitly what is and isn’t made up, so it might be worth saying a few words here to tease out fact from fiction. The story starts off steeped in reality. Our protagonists really did exist, as did the Bone Wars, and the two palaeontologists went to great lengths to outdo each other, as described in the book. However, after this early set up, the story quickly goes off the rails in terms of factual accuracy! While Cope and Marsh might have been liberal when erecting new species, they never made up species out of pure cloth, as happens in Enik’s story. Obviously, Cope did not describe a “NeverTopThisOne-Ginormous-asaurus”, nor did March announce a “WhoAreYouKidding?-Extravaga-saurus”. However, I’ve taken these suggestions on board as possibilities if I ever have an opportunity to name another new species of prehistoric reptile myself! Also, to my knowledge, neither palaeontologist ever used mechanical arms in their digs, though it is a good idea!

The plesiosaur that makes an appearance is, of course, Elasmosaurus, which was pivotal in the real-world Bone Wars. Elasmosaurus was originally reconstructed wrongly by Cope in 1868 with the head on the end of the tail. Despite scrambling to recall all preprints, and despite successfully replacing the erroneous reconstruction with a more accurate one with the head on the right end of the vertebral column, it was all in vain. According to lore, Marsh became aware of the mistake, and swiftly proceeded to place Cope in a headlock and deploy a bout of ‘noogies’ lasting the rest of Cope’s life. Not true (well, perhaps metaphorically so), but Marsh did repeatedly make the most of Cope’s blunder, using it as ammunition in their rivalry and mocking Cope and his “incompetence” at every opportunity. This served to fuel the animosity between the two men, which Jane P. Davidson (2002) has described as “not only a professional rivalry but a genuine hatred of one another”. The story of the Elasmosaurus is so rich and peculiar that I was surprised Enik didn’t make more of it in Sticks ‘n’ Stones. The Elasmosaurus in Enik’s fictional tale is more incidental to the story, a background character portrayed in the artwork, but not referred to in the main prose.

Given the light tone of the book, it would be inappropriate and unfair to cast too critical an eye over the cartoonified Elasmosaurus, so I won’t. Ahh, go on then, I can’t resist, just a little analysis. The swan-necked posture was certainly impossible in all plesiosaurians – the vertebrae don’t articulate that way. The neck is also short by a fair few vertebrae – I count 48 neck vertebrae in one illustration, 28 in another. There were, in fact, no less than 71 neck vertebrae in Elasmosaurus! To go any further with this unjust analysis would be remiss, this is not a text-book, and any book that raises the profile of plesiosaurs and palaeontology in general is good news!

Overall, this is an entertaining and distinctively illustrated romp of a story that I enjoyed thoroughly. I’ll be passing my copy onto my young niece and nephews who, no doubt, will appreciate it just as much as I do.

Available from Amazon.com here and Amazon.co.uk here.

“After 65 million years, the world’s greatest predator is back” – Max Hawthorne
“Oh blimey, we’re gonna die!” – an Englishman in Kronos Rising.

Note – this review contains minor spoilers.

Kronos Rising, the new novel by Max Hawthorne, is a man vs monster story of a giant pliosaur that terrorises a seaside Florida town. Author Max Hawthorne was kind enough to send me a copy of the novel to review and I promised to write about it here.

You might expect some resistance from me towards fanciful notions of pliosaur biology and physiology, but this isn’t the case, I’m always game for some science fiction, no matter how far fetched. Kronos Rising is no text book and it would be ridiculous to review it as such. However, a few comments on the science won’t hurt.

The eponymous pliosaur in Kronos Rising is a new species of Kronosaurus, dubbed Kronosaurus imperator. It isn’t specified what or where the type specimen is, or if the name is recognised by the ICZN, but that’s all by the by! The pliosaur – for there is only one – is a badass, just because, and I’m fine with that. She (it emerges that this pliosaur is female) surpasses bassassery into the realm of super-villainry, for she has a vast array of powers at her disposal. These include: bullet-proof armour, echolocation, infrared vision, a directional and “phenomenal sense of smell”, “sensitive eardrums” with an acute sense of hearing, “amplified power of healing”, “resistance to disease and bacteria”, a swimming speed in excess of 45 knots (52mph), and a bad temper to boot. When it isn’t killing it dreams of killing (no, really!). And, of course, at over 80 feet long (just over 24m), it is huge. Hawthorne goes out of his way to give his Kronosaurus imperator all the bells and whistles and it makes for a terrible foe!

Pliosaurs, of course, were not quite so terrible in reality, no real animal would have all of these adaptations. One sense – the sensitive underwater olfaction the pliosaur uses to track down its prey – is supported by evidence outlined in a Nature paper (Cruickshank et al. 1991), so Hawthorne has clearly done his research and consulted the literature. Most everything else is is speculation. Pliosaurs didn’t have armour or heavy-duty scales and were probably rather smooth like cetaceans are today, a more useful adaptation to an aquatic lifestyle. I’ve written before about the fossil evidence for huge pliosaurs, and the maximum size estimates level off at around 15m. Hawthorne’s speculative 24m long Kronosaurus is therefore an overestimate, but not outside the realms of possibility. We can roll with this – it’s science fiction.

The fascination with large size in the novel extends beyond the obvious immensity of the Kronosaurus itself, to massive boats and guns, strapping muscular men, and anglers out to seek the biggest catch. I know Max Hawthorne is a record breaking angler himself, so perhaps this is a fisherman thing? There are nautical terms aplenty throughout the novel and for that I appreciated the glossary at the back of the book. Still, I found the technical detail sometimes bogged down proceedings – I’m obviously a landlubber.

The novel contains several surprise twists but is generally conventional in both plot and character development. The love story, for example, is spelled out from the get go. The main male and female protagonists share troubled histories over which they can bond and this gives them both depth and motivation, but many of the characters in Kronos Rising come off as rather one dimensional – stereotypes of the genre I suppose. The dialogue, especially some of the innuendo-charged flirtation, made me cringe at times, and the phonetically spelled Jamaican accent didn’t work for me either – it was distracting.

The pliosaur, I noted, only seems to kill men. Perhaps this is some sort of karmic retribution for the monstrous misogynistic acts committed by men against women in this novel? Or, maybe it is simply because there are so few active female characters.

I couldn’t say with certainty where the creature came from in the first place. There are some flash-back scenes to the Late Cretaceous describing how a small population of prehistoric critters came to find themselves enclosed in a caldera during the explosive end to the Mesozoic Era. Incidentally, I should note that the heyday of the apex pliosaur was during the Middle-Late Jurassic and Early Cretaceous, and they became extinct before the end Cretaceous mass extinction event. Nevertheless, exactly how this location and its pliosaur inhabitant remained isolated (under water?) for 65 million years, and the details of the events leading to the release of its occupants into the present day ocean, are unclear. I guess this ambiguity was intentional but it is somewhat unsatisfying. With regard to plot twists I appreciated the tension generated by bringing the combustible mix of characters together in the climax.

In conclusion, this is a novel with obvious echoes of Jaws and Jurassic Park, and it is great to see pliosaurs get the attention they deserve, but I was never completely reeled in by Kronos Rising. There’s surely an audience out there for it, the glowing reviews of Kronos Rising on Amazon.com and elsewhere are testament to that, and indicate that I’m in the minority here! So, pick up a copy and find out for yourself!

Buy Kronos Rising from Amazon.com here
Visit Kronosrising.com
‘Like’ Kronos Rising’s Facebook page

It was once common knowledge that elasmosaurid plesiosaurs were bendy-necked beasts that swanned about near the surface, striking snake-like at slippery prey. It is now common knowledge that their necks were relatively rigid rod-like structures, the function of which remains something of a mystery. The truth, with regard to flexibility at least, is probably somewhere in between. The most recent study to provide estimates of flexibility in elasmosaurid necks gives ranges of motion in the region of 75–177° ventral, 87–155° dorsal, and 94–176° lateral, depending upon the thickness of cartilage present between adjacent vertebrae (Zammit et al. 2008). Visually, that looks something like this:

Ranges of elasmosaurid neck motion as estimated by Zammit et al. 2008.

Elasmosaurids weren’t the completely stiff-necked creatures they’re sometimes made out to be — even a tiny amount of flexibility between vertebrae adds up when you have 70+ neck bones. But why did plesiosaurs have such a long neck in the first place? This is a difficult question to answer because 1. plesiosaurs are extinct and left behind no living descendants, and 2. there are no other extant aquatic long-necked organisms to provide analogues. To my knowledge (and correct me if I’m wrong) there are no long-necked fish, cetaceans, sea turtles, or any other long-necked organisms that spend their entire life underwater. At least not to the extent seen in plesiosaurs.

Elasmosaurids were weirdos, but they maintained this long-necked bauplan for 135 million years, so they were successful weirdos. The long neck also evolved independently in different plesiosaur lineages, some cryptoclidids have extremely long necks too, for example. This all indicates a strong selection pressure (or pressures) driving the evolution of the long neck in plesiosaurs, despite the great risk involved in exposing such a delicate part of the anatomy in an ocean filled with super-predators. The long neck was therefore obviously doing something(s) useful. However, we can only really guess what.

Here are the top possible functions for the long neck in elasmosaurids (I’ve ruled out those possibilities that would require flexibility greater than the estimates given above). Some of these ideas are reasonable and have been suggested before, while others are, ahem, unreasonable and quite ridiculous.

1. Stealth device. Fish are stupid. The long neck provided distance between the bulky body of the plesiosaur and the unsuspecting prey.

2. Getting into tight spots. Helpful for hunting in reefs, crevices, and kelp forests.

3. Sexual selection. The equivalent of a peacock’s tail – the longer and more brightly coloured the better.

4. Food storage. Hamsters have cheeks, plesiosaurs had necks. This might not be as ridiculous as it sounds. Leatherback turtles do something similar (despite their incredibly short necks) by having an extended oesophagus that wraps around the stomach. Their prey (usually jellyfish) is held in place in the oesophagus by backwards-pointing projections (papillae) while excess water is expelled. After temporary storage in the oesophagus the morsels are transported to the stomach. Perhaps elasmosaurids were jelly fish specialists too?

5. Bottom feeding. Hunting in soft sediment. I’m not sure how the long neck really helps here – maybe something akin to number 1?

6. A snorkel. An air supply for staying submerged for prolonged periods of time.

7. Surprise, mother flapper!

8. Energy saver. Moving costs energy, so a long neck might allow the plesiosaur to feed, slumped on the sea bed, hardly moving its body in the process.

9. Electrogenic organ. Plesiosaur necks housed electrocytes and so longer necks create higher voltage electric fields. For electrolocation (sensing prey), elecrofishing (stunning prey to be consumed at leisure), and/or electric defence (to protect from pliosaurs and mosasaurs). This hypothesis comes from here, and was raised to my attention by Darren Naish.

10. Wrench of death. Grab and twist – for pulling ammonites out of their shells. Originally suggested here – thanks again to Darren Naish for reminding me. Twist feeding has also been suggested for short necked pliosaurs, for which it makes morse sense to me.

Other suggestions are welcome! Edit – I’ve updated the list with some new suggestions and will add more soon based on the comments posted below…

References

Zammit, M., Daniels, C. B. and Kear, B. 2008. Elasmosaur (Reptilia: Sauropterygia) neck flexibility: Implications for feeding strategies. Comparative Biochemistry and Physiology, Part A, 150, 124–130.

Many readers will be familiar with the giant plesiosaur on display in the marine reptiles gallery of the Natural History Museum, London. This is a cast of the 7 metre long holotype of Rhomaleosaurus cramptoni, the original of which is housed in the National Museum of Ireland (Natural History) and formed the basis for my PhD thesis back in (time flies!) 2007. However, The Natural History Museum, London, also has its very own massive (also ~7 m long) and quite real Rhomaleosaurus type specimen to rival the ‘Dublin Pliosaur’ in size. NHMUK PV R4853, the mighty Rhomaleosaurus thorntoni, is from the Toarcian (Lower Jurassic) of Northamptonshire. It was donated to the museum prior to 1922 but has never been described and figured in its entirety before.

Rhomaleosaurus cramptoni cast on display in the NHM, London

My newest paper, co-authored with Roger Benson (Smith & Benson 2014), provides a detailed description and photographic atlas of the entire skeleton of Rhomaleosaurus thorntoni, and it was published by the Palaeontographical Society just in time for me to distribute copies to colleagues at the SVP annual meeting in Berlin last November (2014). Few monographs of this kind, i.e. a comprehensive treatments of a single taxon, exist for plesiosaurians, especially up-to-date ones, so the paper should prove useful. The monograph includes 35 photographic plates depicting, essentially, every bone in the skeleton from multiple angles. We describe the skeleton in detail and figure the more complicated elements as interpretive illustrations. It’s just a bigger than average descriptive paper, really, but one that has been many years in the making (even more than it usually takes!). I’ve been waiting for the published monograph to be listed on the Palaeontographical Society publications page prior to posting this article, but since it is not yet forthcoming I decided to post this anyway. I’ll update this blog entry with a link to the volume once it is listed. [Edit – here is the link]:

Rhomaleosaurus thorntoni ilia (Plate 33 from Smith & Benson [2014])

Rhomaleosaurus thorntoni reconstruction. Scale bar = 1m.

There is some doubt over the systematic position of rhomaleosaurids. They are traditionally regarded as pliosaurs, but they might not really be included within that clade, so for this reason we refrained from referring Rhomaleosaurus to Pliosauroidea in the title. We don’t include a cladistic analysis in our monograph to investigate this question, but we do summarise all previous ones and identify areas of relationship consensus within the clade Rhomaleosauridae. More cladistic work is required to confirm whether rhomaleosaurids are an early plesiosaurian offshoot, or pliosaurs proper.

Ingroup relationships of rhomaleosauridae according to different researchers (text-fig 11 from Smith & Benson [2014])

The Palaeontographical Society funded some of my visits to the Natural History Museum to see the fossil material and this influenced my decision to select the Monograph of the Palaeontographical Society as a publication venue for this work. Plus, the format suits such an exhaustive treatment. I’d  like to thank the editor, Yves Candela, who made a significant contribution to the volume and coordinated the whole process.

Update: The monograph is now available for sale from the Pal Soc website here.

References:

Smith, A. S. 2007. Anatomy and systematics of the Rhomaleosauridae (Sauropterygia: Plesiosauria). PhD thesis. University College Dublin, 278pp.

Smith, A.S. 2013. Morphology of the caudal vertebrae in Rhomaleosaurus zetlandicus and a review of the evidence for a tail fin in Plesiosauria. Paludicola 9 (3): 144–158.

Smith, A.S. and Dyke, G.J. 2008. The skull of the giant predatory pliosaur Rhomaleosaurus cramptoni: implications for plesiosaur phylogenetics. Naturwissenschaften, 95, 975-980.

Smith A.S. and Benson R.B.J. 2014. Osteology of Rhomaleosaurus thorntoni (Sauropterygia: Rhomaleosauridae) from the Lower Jurassic (Toarcian) of Northamptonshire, England. Monograph of the Palaeontographical Society, London: 168 (642), 1–40, pls 1–35.

The five metre-long holotype specimen of ‘Plesiosaurus’ megacephalus, from the Jurassic of Street-on-the-Fosse, Somerset, was one of several plesiosaur specimens once displayed in the Bristol Museum and Art Gallery. As one of the earliest plesiosaurs to evolve it is an important species for understanding the early history of the group. Sadly, the fossil skeleton was destroyed along with many other important specimens when the museum was struck by a bomb during the Second World War. This destroyed fossil material is sometimes referred to today as the ‘ghost collection’.

Historical photograph of the holotype skeleton (BRSMG Cb 2335) of Atychodracon megacephalus (Stutchbury, 1846). Bristol City Museum & Art Gallery. Length of skeleton equals 4960 mm.

Thankfully, all was not lost. Moulds had been taken from some of the fossils before the war, and in the case of ‘Plesiosaurus’ megacephalus, multiple casts of its skull and forelimb were produced prior to its destruction. These were deposited in the collections of several museums, including the British Geological Survey (BGS), Keyworth; Natural History Museum, London; and Trinity College, Dublin.

The casts provide a valuable resource that I was able to use to describe ‘Plesiosaurus’ megacephalus in an article published this year in the open access journal Palaeontologia Electronica (18.1.20A p.1-19). The study focused on the casts held in the BGS, but was also facilitated by The Bristol Museum and Art Gallery who provided historical photographs of the ‘ghost collection’ from their archives. The photo (above) shows how the entire fossil skeleton appeared before it was destroyed. The BGS also produced three-dimensional digital laser scans of the casts as part of their JISC-funded ‘GB3D fossil types online’ project. The resulting virtual models are free to view or download (here) and can be rotated on screen or 3D-printed.

Three dimensional scan with texture (colour) removed of plaster cast (BGS GSM 118410) of the holotype (BRSMG Cb 2335) skull of Atychodracon megacephalus (Stutchbury, 1846) in ventral (palatal) view. Scale bar equals 100 mm.

The skeleton of ‘Plesiosaurus’ megacephalus is distinct enough from all other plesiosaurs, including Rhomaleosaurus and Eurycleidus, to warrant a new genus name. I called it Atychodracon, meaning ’Unfortunate Dragon’, in reference to the unfortunate destruction of the original fossil material. This project also demonstrates that casts of fossils, and 3D laser scans, can provide valuable data for palaeontologists – they can be described, measured, and coded into analyses. When original fossil material has been lost, damaged or destroyed, the scientific value of casts increases even further. This study is the first publication to make use of the publicly available repository of 3D laser scans provided by the BGS. The Bristol Museum and Art Gallery is now investigating the possibility of using physical representations of their ‘ghost collection’ in future exhibitions, to bring long lost fossils such as Atychodracon ‘back to life’.

Find out more by checking out the article at Palaeontologia Electronica.

Plaster cast (BGS GSM 118410) of the ventral surface of the right forelimb of the holotype of Atychodracon megacephalus (Stutchbury, 1846) (BRSMG Cb 2335). 1, three dimensional scan with texture (colour) removed, 2, photograph, 3, interpretation.

One of the many areas of controversy in plesiosaur palaeobiology is the topic of how they swam. The question goes back almost 200 years to the 1820s when the first complete plesiosaurs were described from the Jurassic cliffs of Lyme Regis, UK. Plesiosaur swimming is a particularly difficult topic to study for a number of reasons. Plesiosaurs are extinct so there are no modern descendants, they have a unique body plan with no modern analogues, and swimming animals tend not to leave a good trace fossil record. All of this leaves us in a sticky predicament, but there are avenues we can explore to come to a greater understanding of plesiosaur locomotion.

Previous researchers have tried to answer the question of how plesiosaurs swam by conducting detailed osteological analyses, while others have approached it experimentally using robotics, or humans with fabricated paddles. These studies have started to settle on some consensus but there is still some uncertainty. The topic can also be explored experimentally through computer simulation and I was fortunate enough to be involved in such a study in collaboration with colleagues at the Georgia Institute of Technology. Our findings were published today in the open access journal PLOS Computational Biology (Liu et al. 2015).

Rendering of the Meyerasaurus victor plesiosaur model used in the study by Liu et al 2015.

What did we do?

We built a full-size, 3D, virtual plesiosaur, placed it in a simulated fluid, and gave it articulated joints so that it could propel itself through the fluid. We ran thousands of simulations to find the optimal ranges of limb motion and gaits – those that moved the animal forward the furthest. We did so multiple times under different specified parameters to see how different available ranges of joint motion effected the results. To investigate the potential contribution of the different limbs, some of the simulations used all four limbs while others used the forelimbs or hind limbs only. You can check the open access paper for the technical details.

What did we find?

We generated a lot of results in the form of videos. The simulations with the most plausible ranges of motion have a flying stroke with a large up-down component. This is essentially a form of underwater flight similar to penguins and turtles. One of the key questions we wanted to explore was how the forelimbs and hindlimbs moved relative to each other. Our results were inconsistent in this regard, which is significant in itself. The ‘forelimb-only’ simulations are just as fast as simulations using all limbs, which implies that the forelimbs were the powerhouse in plesiosaur swimming while the hindlimbs were more passive, at least during steady cruising.  However, in ‘hindlimb-only’ simulations, where the hind-limbs were asked to do all of the work, the rear flippers flail around a lot but the motion isn’t transferred into thrust or forward motion. Instead, in these simulations the whole plesiosaur rocks around the centre of body mass – apparently a rear-drive plesiosaur is a no-goer. This physical constraint probably explains why no other animals have adopted this unusual body plan, and it also explains why the gait is so variable in our simulations – the hind limbs provide so little thrust during cruising that how they move relative to the forelimbs is irrelevant.

An example of one of the simulations. This one shows optimal swimming in a simulation of all four limbs using the widest joint range parameters. The parameters in this particular simulation are probably beyond the biologically possible limits of the joints, but other simulations had more conservative ranges (see the paper for all the videos).

To help us understand the limb strokes we traced the tips of the limbs. This one shows the limb tip traces for the above simulation, viewed posterolaterally. The hind-limbs in this simulation used only a small proportion of the available range.

Out of curiosity (and not included in the paper), we also manually simulated some specific limb strokes as hypothesised by previous plesiosaur researchers: rowing,  figure-of-8 flying, and modified flying. However, none of these manual simulations were as efficient as the best simulations found in our study through optimisation.

Does the method work?

Can we be sure that the method works and how do we know? Without a time machine we can never be completely certain that simulations of extinct organisms are correct. However, we can test the methods by applying them to models of animals for which their swimming is already known. In this case, our method was applied to several modern day animals including a turtle, a fish, and a frog (Tan et al. 2011). In each modern day animal the simulations were consistent with the biological reality, which suggests that the virtual reality is mirroring actual reality. This gives us confidence in our method.

New questions raised

Our simulations may shed light onto some old questions, but they raise new ones. If the hind limbs weren’t used for steady swimming, why are they so similar in shape and size to the forelimbs? Our study focussed entirely on propulsion but not on steering or stability, so we suggest that the hindlimbs may have helped the animal change direction more efficiently. Another alternative is that the rear flippers may not have been used in steady cruising – the sort of swimming our method focussed on – but may have instead been used for sudden short-lived bursts of speed. This sort of behaviour would be unstable over long distances (and so our method would reject it), but the hind flippers may have helped the plesiosaur lunge at prey or avoid a larger predator.

Tip-traces of the most efficient limb strokes resulting from simulations with all four limbs. The top simulation explored a narrow range of available motion, the middle simulation explored a medium range of available motion, and the bottom simulation explored a wide range of available motion (probably exceeding the biological limits of joint motion).

The future

We hope to explore the above questions about the function of the hind limbs in the future. There’s plenty of scope for other related studies on different plesiosaurs or other extinct swimming animals. For example, we selected a plesiosaur with a generalised morphotype for this study, but plesiosaurs as a group are highly variable. We’d like to look at some of the more extreme morphotypes in the future, the long-necked elasmosaurids and short-necked pliosaurids, to see how the proportions of the body impact the simulations. We also focussed all of our attention (and computing power) on how the limbs move, because that was our main focus. However, we acknowledge that the tail and neck may also have been important in locomotion. This is something else we hope to explore in the future. In the meantime, every journey must start with a first step, or – in this case – a first flap.

Liu S, Smith AS, Gu Y, Tan J, Liu CK, Turk G. (2015) Computer Simulations Imply Forelimb-Dominated Underwater Flight in Plesiosaurs. PLoS Comput Biol 11(12): e1004605. doi:10.1371/journal.pcbi.1004605

Tan J., Gu Y., Turk G., and Liu C. K. 2011. Articulated swimming creatures. ACM Transactions on Graphics, 30(4), 58:1–58:12.