My take on english taxa #1

So I’m beginning a new series on english taxa, starting with the oldest of any, Rutellum impicatum. Now this name currently is invalid, but it has a very important story to tell. A single tooth was collected near Whitney, Oxfordshire, and later described as a “fish tooth” by Lhuyd. Now in 1699, when this was published, all fossils were simply believed to be fakes, pretty much rocks made by the earth that resembled animal bones. Lhuyd had a habit of describing all his “rocks” and giving them latin names, and for this tooth he chose Rutellum impicatum, meaning “pitch covered shovel”. Lhuyd also figured this tooth and provided a description, stating that the tooth was bright black and was found near “Caswelliana” near Whitney, Oxfordshire. However, according to Delair and Serjeant (2002), there is no civilization named Caswell anywhere near Whitney, and the closest Caswell is apparently in Wales. But Delair believed that Caswell was a simple misspelling for Carswell. Any british people can easily give me pointers on what I get wrong, as these are your cities and bones.

Rutellum is often noted to be a cetiosaurid based on the mid-jurassic age and location, however, I have noted that Rutellum bears and lacks many features similar with other sauropods, and based on simple morphology it appears to be intermediate between Shunosaurus and Cetiosaurus? teeth. But one intriguing thing is that the tooth bears a single feature that is only shared with Camarasaurus among sauropods, an anteroventral projection of the crown ventral to the dorsal edge of the root. This is about it for Rutellum, but I give you the only known illustration of the tooth, which is now lost.

Rutellum tooth

  1. Delair, J.B., and Sarjeant, W.A.S. (2002). The earliest discoveries of dinosaurs: the records re-examined. Proceedings of the Geologists’ Association 113:185–197.
  2. Lhuyd, E. (1699). Lithophylacii Britannici Ichnographia, sive lapidium aliorumque fossilium Britannicorum singulari figura insignium. Gleditsch and Weidmann:London.
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Haestasaurus

Haestasaurus becklesii is a moderately sized macronarian from the Wealden of England. It was known as “Pelorosaurus” becklesii for a long time since its original description, with its humerus, the only overlapping material, significantly more robust than that of Pelorosaurus brevis. In the middle of summer this year, Paul Unchurch, Phil Mannion, and Mike Taylor published the first detailed redescription. Among the known material is the humerus, associated with a radius, and an ulna. But quite uniquely among all sauropods is the association of a skin impression with the elbow region of these remains. The scales are large and non-overlapping, but based on photographs I’ve seen they become smaller towards the edge of what is preserved.

Haestasaurus skeletonThe systematics of Haestasaurus have been under question for some time, and it was considered to be a primitive titanosaurian for some time. However, two of the three analyses found it to be a primitive macronarian, either a camarasaurid, or a non-camarasauromorph macronarian.

The skin impression of Haestasaurus, lies on a joint, a region where predators may attack to main an animal. That makes it seem like the more attacked regions would have had similar scales – the hindlimb, the underside, and the neck. Thus, In my life restoration based on the above skeletal which is also mine, I have added these pebbly and larger scales to these regions.

Haestasaurus reconstruction

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Why Not to delete taxa A Posteriori or A Priori

So I’ve been making excursions into phylogenetic analysing, and based on advice from Mike Taylor I’ve added a dental character, Euhelopus and Brachiosaurus nougaredi. Based on what I’ve found, I can safely say that NO MATTER WHAT, all characters and taxa add to an analysis, and if there is a dissolved clade that you want resolved, add more taxa or characters.

The strict consensus, which is the only really important analysis, is resolved as (Outgroup (Cetiosaurus, H. priscus, H. delfsi, H. sp., H. utterbacki, Tataouinea, Camarasaurus, Brachiosaurus, B. nougaredi, Futalognkosaurus, Apatosaurus minimus, Atlantosaurus, Euhelopus (A. ajax + Elosaurus) ) ). Now, Atlantosaurus is a pretty bad taxa, second worst known after B. nougaredi in this analysis, so I removed it in one analysis. This generated the tree (Outgroup, all other taxa), which actually dissolves the clade of A. ajax + Elosaurus. Now for the final analysis I removed B. nougaredi, and the tree was resolved as the exact same as with all taxa except without B. nougaredi.

This shows that neither tree was improved by removing a single fragmentary taxon, but to prove my point further I decided to remove both and generate a tree. With both removed, the tree resolved the same as with only Atlantosaurus removed. Now for some reason Atlantosaurus is the taxon that supports the clade of A. ajax + Elosaurus, but I’m not sure how.

I think this is good proof that analyses are better with more information, and further analyses should put this into account before deleting A Priori or A Posteriori.

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A Phylogeny of Pure Sacral Characters

I have for a while been intrigued by sauropods, and how Atlantosaurus related to Apatosaurus. Of course because the former would be the senior synonym. But I didn’t want to code it into a large analysis. So I decided to place it in a purely sacral-based analysis. So I (somehow, honestly I’m not sure how, but I think it was a trial version) got PAUP* for free and added in my matrix. In the analysis, with the matrix based on my observations of photographs, with characters after multiple authors including Tschopp et al..

There were 25 characters, and 13 taxa, so not exactly the most comprehensive analysis. The outgrip was hypothetical, and all zeros. Taxa included were CetiosaurusFutalognkosaurusBrachiosaurusCamarasaurusElosaurusApatosaurus ajax, A. minimumAtlantosaurus, and the three proposed species of Haplocanthosaurus in addition to H sp. I expected to see the normal group with Cetiosaurus as most basal, diplodocoidea formed, and macronaria together. However, something strange happened.

Like proposed by Mike Taylor and Matt Wedel, Apatosaurus minimus grouped with Camarasaurus and Brachiosaurus. Both the strict consensus and 50% majority trees were similar, with the strict consensus simply more dissolved. Cetiosaurus was most basal other than the outgroup. But up next was a polytomy of Futalognkosaurus and Atlantosaurus. This is strange, as normally these two fall into the ends of separate neosauropoda. Up next was what would normally be Neosauropoda. This split into two groups, Presumably diplodocoidea and macronaria. However, the split seemed to be more Rebbachisauridae/Diplomacronaria. In Rebbachisauridae was a clade of (Haplo delfsi, Haplo priscus (Haplo sp. (Haplo utterbacki + Tataouinea) ) ). And then there is Diplomacronaria, which is just a name I made up. It includes (Apato ajax ( Elosaurus ( Apato minimus (Camarasaurus + Brachiosaurus) ) ) ). This is really quite a weird result, but I think it could be expected with the small number of taxa and the purely sacral-based matrix. Both the strict consensus and 50% majority trees are shown below.

50% majority tree

50% majority tree

Strict consensus tree

Strict consensus tree

Things to note include that there were 15 possible trees for the strict consensus. In the analysis, when there was more than one species the first letter is directly following the generic name. I can provide people with the nexus file if they would like it.

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A Sneak Preview (publication #1?)

Hi all. It is about time for a post on what very well may be my first publication. First off, journal choices.

So with every publication, the author has to chose a few journals to submit the paper to, with an order. I’m quite fond of open access, so I would like my first paper to be published with it. So there is a list of journals to submit it to, PLOS journals, Acta Palaeontologica Polonica, PeerJ, and others. The above three are my preferential journals, but with them come some restrictions. PLOS journals are quite renowned for there cc license, large manuscripts and impressing figure sizes, but they also have multiple limitations. The first one is cost. PLOS charges about 300±100$ per paper, which is quite a lot for amateurs like me. This basically crosses it off my list. Act Pal Pol is similar, but I think it charges slightly less, but with limits on size. Now note, my paper is not planned to be lengthy, and based on what I have written I don’t think it will be. Act Pan Pol thus goes on my “maybe” list. Now for PeerJ. I have heard a lot of positive comments on PeerJ during its lifetime, and it is my favourite to publish this paper in. PeerJ also offers PrePrints, and for certain, I am going to submit this paper to them before any form of peer review. Now PeerJ is relatively new, but it publishes any paper for around 10$, assuming that the author publishes 9 papers with PeerJ in their lifetime. With this 99$ lifetime membership you get about one paper per year, as long as you review manuscripts for free. After my non-so critical evaluation of all the open access journals I’d like to publish in, PeerJ comes out top.

Yay, so PeerJ will get my paper submitted to them. Now onto the true publication. So I live in Canada, and there is one province I like the most, with a very unique fossil assemblage, British Columbia. Now B.C. has arguably the best known deposit in North America for any fossil enthusiast, the Burgess Shale. But there is one thing unfortunate about this shale, it is 300 million years to old. So no-one is going to find a dinosaur in those fabulous rocks. Within Canada, Alberta comes first for dinosaur skeletons, but British Columbia roughly ties it for most dinosaur fossils. You see, Alberta is very plentiful in skeletons, but only two or three footprints are known. While British Columbia is relatively rare in dinosaur skeletons, but is known from many, many trackways and footprints. Now these trackways were all reviewed in 2014, so a paper on them wouldn’t be very interesting. But what hasn’t been reviewed since 1983, are the dinosaur body fossils in the province. So this is what I decided to review. No more info, but one picture, of a single manual phalanx from a boring ornithopod, from Sampson & Currie, but shaded by me based on Mike’s fabulous GIMP tutorial.

Major Update: For all those who care, the above paper has now been accepted by PeerJ as a PrePrint, available here for all those who would like to view it. My article will now be going to PeerJ, as it is not within the scope, but I am currently submitting it to Palaeo Electronica, so I’ll see how that goes.

References:

Sampson, S.D. & Currie, P.J. 1996. On the Trail of Cretaceous Dinosaurs. In Life in stone: a natural history of British Columbia’s fossils. Edited by R. Ludvigsen. UBC Press, Vancouver, B.C., pp. 143–155. ISBN:0-7748-0577-3.

Ornithopod phalanx

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The tail of the past

Been doing some research on Prodeinotherium and the relatives, for no reason. And somehow I came across some excellent new dinosaur illustrations on wikipedia. We have relatively strict rules for image inclusion, such as anatomical accurateness. However, apparently the images are highly accurate, and two are even based off of work by Greg Paul. One of these was a Tuojiangosaurus, and I wanted to verify that it followed what it was based on. Thus, I got on the google book for the Field Guide, and checked out Greg’s Tuojiang. There were other stegosaurs in the guide so i viewed them one at a time. Then I came across him Huayangosaurus. Immediately, there is something peculiar I noticed, tying in with some old posts of SVPOW. There was a tail club!

I found this interesting, and thus wanted to check out if this was an accurate portrayal of Huayang. Online many illustrations (presumably based on Paul’s skeletal) had these club, but there was a rarity of pictures of a Huayang skeleton. So I was wondering if anyone who reads this blog has anything to say about the antiquity of the tail club on Huayangosaurus.

Anyway, there are some interesting thing about how this relates to other thyreophorans. Scutellosaurus was likely an ancestor or close relative of the ancestral thyreophoran, and it had, true to its name, a covering of scutes. However, the tip of the tail is unknown, so there is little more it is involved in with this post. Later are genera such as BienosaurusEmausaurus, Lusitanosaurus, and Tatisaurus. But no tail is known from these either (as i recall). Scelidosaurus is next in the thyreophoran line, and sadly, the very end of the tail is unknown. But, based on the Sole specimen, the tail would have had scutes that get smaller toward the end of the tail, and maybe a scute at the end of the tail.

Now for a speculation. If there was a scute at the tail end, I predict that it evolved into a small club, before the stegosaur/ankylosaur split. Then at this split stegosaurs gradually became more slender and lost use for a club past Huayangosaurus. And ankylosaurs became more bulky and gained a larger club, before splitting, with nodosaurids evolving slenderer and gradually losing there club, and ankylosaurids becoming bulkier and possessing a larger tail club.

Of course my speculation is just that. And even if Scelidosaurus and Huayangosaurus had a club, that does not necessarily mean that a club was ancestral.

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Comments on “The Osteology of Hypselospinus” Norman, 2015

I find a few things troubling about the recent publication on the Osteology of Hypselospinus, published recently in the Zoological Journal of the Linnean Society, authored by David Norman. Most importantly are the systematics. The new clade Clypeodonta is defined, as HypsilophodonEdmontosaurus. Norman also redefines Hypsilophodontia, to be HypsilophodonTenontosaurus. This is very problematic, as even though it works for Norman’s phylogeny, many, many other analyses find Tenontosaurus just outside Iguanodontia, so in those many, many other phylogenies these groups are synonymous by definition, as they are also both node-based.

Even more troubling is Norman’s redefining of Iguanodontia. It was relatively well-defined before, and the included taxa were relatively stable. But Norman topples this, redefining it as Edmontosaurus > Hypsilophodon + Tenontosaurus. This is ridiculous. The definition is totally useless unless Hypsilophodon and Tenontosaurus are grouped together, and this is the only time they have been.

Norman used a definition of Ankylopoxellia that I have no problem with, but then again he causes issues with his definition of Stracosterna. As far as I know, only Norman’s phylogeny finds Batyrosaurus the most basal Iguanodontian more derived than Camptosaurus, yet Norman still redefines Styracosterna as Batyrosaurus + Edmontosaurus. The previous definition of Edmontosaurus > Camptosaurus makes much more sense and is much more stable.

Norman’s other definitions are much less troubling than these, yet I do not know why he changed the Edmontosaurus > Iguanodon definition of Hadrosauriformes to make it node based Altirhinus + Edmontosaurus.

*Note: I assume the definitions of Hadrosauriformes and Styracosterna to be as I have put them, but they may be slightly different.

Update 5/13/2015: I now see how little is known of Batyrosaurus, which makes me feel there is even less support for Norman’s Styracosterna. As well, I believe Norman needs to include many more taxa, such as the many other Styracosternan’s (by the conventional definition) and other Hadrosauroids. And a final note, Norman does not even use Hadrosauroidea as a group, which he very well should as it is much more used than his new Hadrosauromorpha.

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