I figured if I was going to do a Jurassic World-related post on Stegosaurus I might as well follow it up with a review for the film. I grossly underestimated the draw of dinosaurs to the cinema. Despite 22 years of Jurassic Park, Walking with Dinosaurs (BBC version, not the Disney thing), and so on, people never seem to be burnt out on dinosaurs. That’s good news for paleontology (yay!), and also for movies seeing as how Jurassic World just raked in a record-breaking $208.8 million domestic in its opening weekend.
So what did I think?Â In short: I liked it and found it to be a worthy successor to the franchise.
As I write this the US premiere of Jurassic World is just around the corner. I had gone back and forth regarding this post given that we currently know very little about the film and as such the interpretations written about here and elsewhere may well be pointless by the time the film premieres.
Ultimately I decided to post this anyway since the overall thrust of the article should remain true regardless of how the film pans out.
Now there has been a lot of buzz around Jurassic World since it was first announced last year. The buzz has been mixed, but fairly positive. I suspect this was, in part, because everyone was happy to hear that the godawful military dinosaur idea was shelved in favour of a more “traditional” JP franchise storyline. Nonetheless the movie has still drawn its fair share of detractors, including myself. Most of the people who are unhappy with the film are either paleontologists, or hardcore dinophiles. Many of the problems leveled at the film have to do with the portrayal of the extinct animals. The problems are actually myriad ranging from pterosaurs capable of picking up humans using grasping feet, mosasaurs that are twice the size of blue whales, sauropods covered in elephant skin rather than scales (a problem not unique to Jurassic World),Â everything aboutÂ Velociraptor, and of course Indominus rex.Â My biggest beef with the film is that the dinosaurs are not being shown as dinosaurs so much as monsters. However, after The Lost World: Jurassic Park came out it became pretty evident that Spielberg’s original vision of portraying dinosaurs as animals had been shelved in favour of the more entertainment-friendly movie monster approach. However, for what seems like a majority of the detractors, the biggest gripe with the film has to do with a lack ofÂ feathers on pretty much all the dinosaurs. This seems to be a common theme these days with a particularly vocal group of dinophiles and paleontologists strongly pushing for the feathering of every dinosaur in sight and insisting that all media that portrays scaly (erroneously called: “naked”) dinosaurs is inaccurate. Never mind the fact that a feathered, pack-hunting, 2 meter tall Velociraptor mongoliensis is still every bit as inaccurate as a scaly one.
Anyway, I digress. Dealing with the overwhelming amount of internet drama surrounding Jurassic World (and the media depiction of dinosaurs in general) is a topic for another day. My reason for writing this post is centered around one particular criticism that popped up a few weeks ago.
Visitors to the site may have noticed that it has been stuck in archive mode for the past however many months. This only recently came to my attention when I had noticed a lack of update nags from WordPress. Further investigation revealed that comments were no longer going through, nor were new posts. Given the global lockdown of the site I suspected that I was either hacked (again!) or that there was a database issue. A quick scan from Sucuri eliminated the first option (or at least made it less likely), which led me to check the database.
Lo and behold I found that the Reptipage database is currently holding atÂ approximately 150 MB. Unfortunately,Â my current webhost (1and1.com) had a hard limit of 100 MB for databases at my current hosting level. I say “had” because they have since bumped database sizes up to 1GB. The problem was that any old databases currently in use were still subjected to this hard limit. I was 50MB over the hard limit so the MYSQL database was locked down. Hence the lack of updates, comments, posts, etc. I would have caught this sooner, but the demands of my current job have caused the site to get backburnered.
The site is now on a new database that has more legroom to it and I’m now aware of this looming problem (the DB isn’t 1GB now, but it will be in the future). I’m looking into spreading the Reptipage across a few databases using the hyperDB plugin. We’ll see where it goes.
Also, there has been a bit of a lull in my current workflow that has freed up some time that I intend to devote to writing again. Between T. rex autopsy and Jurassic World (both coming out in a few weeks) there is no shortage of excitement, controversy and overall butthurt on the internet that I can talk about. There has also been a bevy of cool new things regarding extant reptiles which I intend to get back to covering.
So that is the current status of things. I have some posts in the hopper that should be coming out shortly. I apologize for having the site in archive mode for so long.
I finally got around to making the site more social-media friendly. You should now have the ability to easily share posts on all the major social media services.
I also fixed a bug in the CSS that kept the font colour for the author fill-in fields black. My apologies to everyone who has been commenting in spite of the problem. I was not aware of it until recently. I also wasn’t aware that you could not subscribe to comments, so I fixed that problem too. You can now subscribe to posts with or without commenting. You can also receive notifications for just replies to your comments if that is what you prefer.
Hopefully the site is a bit more user friendly now. Let me know if anything else is broken.
[Update: I also updated the theme from (which I had not changed since 2007). The old theme would not allow for threaded commenting, which can be extremely frustrating when there are extensive comments. The new theme allows for this and a host of other things too. Now I just need to fix about a dozen small little bugs and things should be good.]
Well, as is often the case, this post is a bit late to the party, despite starting early. Unless you have been living under a rock (or don’t care that much about dinosaurs), you have probably heard about the discovery of a small ornithischian from Siberia, Russia that apparently sports feathers as well as scales on its body. It’s a crazy half-and-half animal that has given many the green light for making all dinosaurs feathery.
As is often the case with these studies I am writing to urge caution against taking things too far, if just so there is some voice of dissent out there in an internet fully of trigger-happy feather reconstructions.
One of the quintessential depictions of prehistoric times is that of an ancient, often volcano ridden, landscape full of animals bearing large showy sails of skin stretched over their backs. Sailbacked animals are rather rare in our modern day and age, but back in the Mesozoic and Paleozoic there were sails a plenty.
By far the most popular sailbacked taxa of all time would be the pelycosaurs in the genus Dimetrodon. These were some of the largest predators of the Permian (up to 4.6 meters [15 feet] long in the largest species). Dimetrodon lived alongside other sailbacked pelycosaurs including the genus Edaphosaurus. These were large herbivores (~3.5 m [11.5 ft] in length) that evolved their sails independently from Dimetrodon. The Permian saw many species of sphenacodontids and edaphosaurids, many of which sported these showy sails (Fig. 1. [1â€“8]).
However sails were hardly a pelycosaur novelty. The contemporaneous temnospondyl PlatyhystrixÂ rugosus (Fig. 1 ) also adorned a showy sail.
Fast forward 47 million years into the Triassic and we find the rauisuchians Arizonasaurus babbitti,Lotosaurus adentus, Xilousuchus sapingensis, and Ctenosauriscuskoeneni ,Â all bearing showing sails on their backs (Fig. 1 [10â€“13]). Much like in the Permian, many of these taxa were contemporaneous and, while related, many likely evolved their sails separately from one another.
There are currently no fossils of sailbacked tetrapods in the Jurassic (as far as I know. Feel free to chime in in the comments if you know of some examples). However the Early Cretaceous gaveÂ us a preponderance of sailbacked dinosaurs (Fig. 1 [14â€“19]) including the cinematically famous theropod Spinosaurus aegyptiacus, the contemporaneous hadrosaur Ouranosaurus nigeriensis, the gharial-mimic Suchomimus tenerensis, the potentially dual sailed sauropod Amargasaurus cazaui, as well as the allosauroids Acrocanthosaurusatokensis, and Concavenator corcovatus. Lastly, the discovery announced last year (and just now coming to light in the news) of better remains for the giant ornithomimid DeinocheirusÂ mirificus have revealed that it too may have sported a small sail along its back.
Once again we find a group of related, largely contemporaneous, animals, most of which probably evolved their sails separately.
Such a huge collection of sailbacked animals all living around the same time (and sometimes the same place) has begged for some type of functional explanation. The usual go-to for large, showy surfaces like these or the plates of Stegosaurus has been thermoregulation. The thinking being that blood pumped through a large surface area like this, when exposed to the sun, has the ability to warm up faster than other areas of the body. Conversely when the sail is placed crosswise to a wind stream, or parallel to the orientation of the sun, heat will radiate out into the environment faster than other areas of the body. That most sailbacked dinosaurs were “localized” to equatorial areas, coupled with the large sizes of all the taxa (1-10 tonnes depending in species) has favoured a cooling mechanism function for dinosaur sails. Whereas a heating function has been presumed to be the primary function for sails in Dimetrodon and Edaphosaurus. No real function has been ascribed to the sails in rauisuchians or Platyhystrix, though this is probably due to a lack of knowledge/interest in these groups.
Alternate functions proposed for these sails have included a self-righting mechanism for swimming, sexual signaling and other presumed display functions. In certain cases, namely Spinosaurus aegyptiacus and Ouranosaurus nigeriensis, it has even been argued that the enlarged spines did not support a sail, but rather were supports for a large, fatty hump akin to that of camels or bison (Bailey 1996, 1997).
Given the wealth of hypotheses for potential sail functions it would be beneficial to first understand what extant sailbacked taxa use their sails for. Unfortunatelyâ€”though unsurprisinglyâ€”there are few if any scientific studies on sail use in extant sailbacked animals. This has lead to the apparent assumption that there are no extant vertebrates with sailbacks.
There are, in fact, quite a few sailbacked animals alive today. These include various fish, amphibians and even reptile species. Learning what these taxa use their sails for may offer us a glimpse at what extinct animals were doing with their sails. Continue reading → Post ID 1374
Last year was a busy year for me. As such the site had to go into dormancy yet again. This year doesn’t look to be any less hectic, but I couldn’t bear to have the site continue to stagnate. So in an attempt to jump-start things again I am going to try and push out some smaller updates.
Which brings us to our topic.
The Reptile-Database recently released the current known/generally accepted species count for reptiles. It is now at a whopping 9,952 species! For comparison, when I was growing up the standard species count for reptiles hovered around 6500â€“6700 species. In fact one can still probably find this widely cited figure in books today. Even when I started the Reptipage some 16 years ago, the total species count was approximately 7,500 species. So in the span of those 16 years, our knowledge of extant reptile diversity has grown by 33%. That’s pretty impressive. Especially when compared to other amniotes. For instance birds are routinely cited as having 10,000 species. The most recent species count for Aves is: 10,530 (IOC World Bird List), an increase of just 5.3%. Mammals were cited as having 5000 species when I was growing up. The most recent (2008) count I could find shows that this class now contains 5,488 species (IUCN Red List); an increase of only 9.8%.
Part of the reason for the larger spike in reptile species counts vs. mammals and birds is due to a new interest in reptiles themselves. Much of the history of Reptilia is one of revulsion, lumping, and overall wastebinning. However, now with the rise of herpetoculture and the acknowlegement that reptiles represent more than just a “stepping-stone” towards mammals and birds, herpetology has seen a bit of a renaissance in taxonomy. Another reason for this spike in species counts for reptiles can be attributed to the use of molecular techniques to ascertain differences in populations, along with better morphological data (such as those used to help determine that Crocodylus suchus was a real species and not just a variant of the C. niloticus) as well as better ecological data. This spike in species count has come about largely through the elevation of subspecies rather than the discovery of new species (though that is still happening). Herpetology has had a long history of lumping taxa that seem similar enough. This reluctance to split populations into distinct species rather than populations variations had artificially limited the actual species counts. Along with the elevation of subspecies to full species, there has also been a trend to elevate many subgenera to full genus status. This move is somewhat more controversial as the question always pops up of what the ever moving criteria for a genus are. Of course the criteria for species are hardly set in stone either. Ultimately taxonomy is a largely arbitrary affair of biological bookkeeping. Despite this, the need to have these criteria is paramount. The human brain doesn’t work well without categories, even if they are largely self-imposed ones. The appeal of splitting up Reptilia like this is that it reflects a changing attitude about reptiles in general. Though it has been long known that reptiles outnumber mammals, there always seems to be an undercurrent of “but they’re all just the same lizard.” A view that reptiles may be speciose, but are still limited in their body shapes compared to mammals and birds, still pervades today. Hence one reason why there are 29 orders of mammals, some 23 orders of birds, but only 4 orders of reptiles. A move to upgrade subspecies to species and subgenera to genera adds greatly to dispelling the myth that reptiles are the forgettable “intermediate forms” on the tree of life.
Regardless of these higher order relationships it looks like Reptilia will officially comprise over 10,000 species by the end of the year [Note: See the comments].
This year has seen the discovery of two big deal dinosaur specimens. At least they are a big deal in regards to dinosaur integument and, possibly, metabolism.
First off from a few months ago we had the announcement the theropodÂ Yutyrannus hauli, the “beautiful feathered tyrant.”
Xu, X., Kebai, W., Ke, Z., Qingyu, M., Lida, X., Sullivan, C., Dongyu, H., Shuqing, C., Shuo, W. 2012. A Gigantic Feathered Dinosaur from the Lower Cretaceous of China. Nature. Vol.484:92-95
This was not just a single fossil, but a collection of three fossils (one might be tempted to call it a family group, but that would only be speculation). As with all other dinosaur fossils that have been found to have filamentous integument, these guys come from Liaoning, China. They are suspected to have come from the Jehol Group in the Yixian formation. I say suspected because the complete three specimen set was a purchase from a fossil dealer, an all too common occurrence for Chinese fossils. As such the provenance information is unknown. A lot of Chinese fossil dealers don’t like to give away the location of their find due to the potential loss of other profitable specimens. This current trend in China is a good example of what happens when capitalism comes into play with fossil collecting (something that the U.S. has been mostly, but not entirely, able to avoid). So it is currently uncertain whether these fossils are from the Yixian. However given that all the others guys are too it is probably a good bet. Given the sketchy nature in which many Yixian fossils are collected, coupled with the possibly large consequences of the find, one should naturally be skeptical of the fossil. Had it been one individual on multiple slabs I would question its validity as a real thing. However since Y.huali is known from three individuals, and the filaments seem to follow a consistent pattern around the body (compare that to the helter-skelter nature of Tianyulong‘s preservation), forgery seems unlikely. These guys are probably the real deal. This has some potentially far reaching consequences to interpretations of Late Cretaceous coelurosaurs and the Jehol Biota itself (more on this in a bit).
The second announcement came just a few weeks ago. This was the discovery of a potentially new, miniscule theropod from Bavaria Germany.
Rauhut, O.W.M., Foth, C., Tischlinger, H., Norell, M.A. 2012. Exceptionally Preserved Juvenile Megalosauroid Theropod Dinosaur with Filamentous Integument from the Late Jurassic of Germany. PNAS Early Edition:1203238109v1-201203238.
The specimen is exceptionally well preserved. So well preserved in fact that it actually looks like a plastic toy. While this degree of preservation warrants importance all its own, the main interest behind this new guyâ€”dubbed: Sciurumimusalbersdoerferi (AlbersdÃ¶rfer’s squirrel mimic)â€”is the apparent presence of filamentous integument on the body coupled with its apparent placement among much more basal theropods. This discovery has far reaching consequences for theropod integument interpretations. Note: As with Y.hauli, Sciurumimusalbersdoerferiwas also purchased from a private collector. I don’t suspect forgery here either as this was in Germany, where fossil dealing is neither a big problem nor a lucrative business. The exceptional detail on the specimen would also require a substantial amount of theropod knowledge to pull off. Anyone having that amount of knowledge is more likely to be a real paleontologist than a get rich quick forger.
As folks earlier this week might have noticed the site was blacklisted by Google. It turned out some hacker’s bot had infiltrated my WordPress account and inserted a bunch of nasty redirects to malware sites.
Getting hacked at any time is shitty, but finding the free time to deal with this was problematic. I have spent many late nights (leading to early mornings) this past week trying to fix things. The hardest part wound up being the frigging permalinks. On the bright side the site is back in working order. This was a sobering reminder for me to take better care of my site, lest some malware bot look at it as abandoned property. Real life work has kept me distracted from the site, reducing its output considerably. I intend to fix this soon as I have a few posts simmering and almost ready for prime time. I intend to keep the Reptipage up and running for as long as possible. That includes keeping it updated with new content.
Sorry for the delay folks. We can now return to our regularly scheduled blogging.
Just announced today in Science, researchers at the Marshall University and the Los Angeles County Museum described the presence of fossil young inside the body of the plesiosaur: Polycotylus latippinus. The results of their find seem to confirm what has been suspected for quite some time now, that plesiosaurs were viviparous animals.
O’Keefe, F.R., Chiappe, L.M. 2011. Viviparity and K-Selected Life History in a Mesozoic Marine Plesiosaur (Reptilia, Sauropterygia). Science. Vol.333(6044):870-873
The evidence had been mounting for some time now. While plesiosaurs came in numerous shapes and sizes, most of those sizes were in the large to giant range measuring in at multiple tonnes (e.g. Liopleurodon and Kronosaurus). That is a lot of weight to attempt to drag up on a beach for egg laying. Further, though the rib cage is well braced ventrally, the limb girdles are not braced against the vertebral column. This would make it very hard for a large landlubbing plesiosaur to make any kind of headway as the limbs would have no leverage against the body for dragging itself on land.
Lastly, and perhaps most importantly, we have known of at least one plesiosaur fossil that had embryos in it. This has been known for at least five years now (I learned of it four years ago, and it has been hinted at before [Smith 2008]). Sadly this specimen still remains unpublished. This new paper by O’Keefe and Chiappe goes on to mention the relatively large size of the young, estimated at 1.5 meters when born. This was much larger than the young of other large extinct and extant marine reptiles. The authors (cautiously) suggest that this might hint at a different life history for plesiosaurs vs. other marine reptiles. They posit that plesiosaurs might have nurtured a small amount of relatively large young, which in turn might have meant that they were more social than previously thought.
Naturally this has resulted in the inevitable comparison to whales. While a “pod of plesiosaurs” does sound interesting, we have far too little evidence to say if such a thing ever happened (and the authors state this too). What we do know is that young plesiosaurs have been found in shallow marine settings. These have been posited to have been “nurseries” where young could stay out of sight from predators while reaching adult size (Martin et al. 2007). Whether, or not adults stayed around, or if they joined a “pod” later (if at all) is all unknown. Still, it is nice to see some validation to what seemed almost necessary for so long.
Admittedly not everyone is convinced (a good thing to see in science). Dr. Ken Carpenter of the Utah State Museum offered Science magazine a dissenting view, suggesting that the position of the young could still indicate that these were juveniles that had been eaten. The O’Keefe and Chiappe considered this in the paper and pointed out that the skeletons lacked any signs of acid etching, as well as showed numerous skeletal bones that did not appear fully ossified. Further analysis could shed more light on this. Publishing on that other plesiosaur could really help things out too.
Assuming that we are looking at viviparous plesiosaurs, that just leaves two other large marine reptile groups of the Mesozoic. Turtles and Crocodylomorphs. In both cases we have extant animals that are obligate oviparous animals, but there might still be reason to think that live birth might have evolved in these groups too. Again, much like with the plesiosaurs, the groups in question (protostegid sea turtles and the podocnemid Stupdendemys, as well as metriorhynchid crocodylomorphs) have members that grew extremely large. While Protostega gigas may have been able to haul itself out on land as extant leatherbacks (Dermochelys coriacea) do, it seems harder to justify that in the much larger Archelon ischyros; an animal that has been estimated to tip the scales at 2 tonnes. Given the amount of effort it takes a large female leatherback (~1 tonne) to haul herself up and down a beach (not to mention the damage it causes to the animals in the short term), it would be all the more amazing if A.ischyros was able to pull off such a feat. The same would go for the metriorhynchids, who had adapted completely to a marine lifestyle (i.e. they had flippers and a tailfin). If a 5 meter Gavialis gangeticus can barely move around on land, I’d hate to see what a 5 meter Dakosaurus would look like. To date we have no evidence one way, or the other for these last two groups. There is a bit more resistance to the idea of viviparity in these groups as no extant members exhibit viviparity. This has lead some to wonder if the calcified eggs of archosaurs (and many chelonians) might prove a phylogenetic constraint on live bearing (the young absorb calcium from the shell, which could mess up calcium absorption in a taxon evolving along the lines of viviparity). The chelonian shell — in turn — may also have been constraining on the size of young that can be held in the body cavity. Still, to date, there are no nests, eggs, or embryos for any of these taxa, thus leaving the matter open for debate. It is interesting that neither protostegids, nor metriorhynchids got to the huge sizes of mosasaurs, ichthyosaurs and plesiosaurs, but that could have been for any number of reasons including the simple lack of finding the larger taxa yet. Until then the physics vs. phylogeny argument remains unresolved.
Anyway, compelling evidence for live bearing in at least some plesiosaurs. Woohoo!
Martin, J., Sawyer, F., Reguero, M. Case, J.A. 2007. Occurrence of a Young Elasmosaurid Plesiosaur Skeleton from the Late Cretaceous (Maastrichtian) of Antarctica. 10th Int.Symp.Antarctic Earth Sciences.
O’Keefe, F.R., Chiappe, L.M. 2011. Viviparity and K-Selected Life History in a Mesozoic Marine Plesiosaur (Reptilia, Sauropterygia). Science. Vol.333(6044):870-873