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?]

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.

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!

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.

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.

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.

'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.

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.

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…

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.)