Thecodontosaurus antiquus, a sauropodomorphan from the Durdham Down region of Bristol, England, is a rather ordinary sauropodomorphan. It’s not that there’s not anything special about it — for there are quite a few — but that it seems so … ordinary. It didn’t have some peculiar nose like the “plateosaurids,” it didn’t have particularly curved teeth, nor did it seem to have special feet or hands. It was just … ordinary. Continue reading
Nick Longrich has a new publication out, with fellow colleagues from Texas, discussing the taxonomy of a few new oviraptorosaurs. Following up on their earlier publication describing “Leptorhynchos” gaddisi, Longrich et al. have fixed the error of not having fixed a type species for their new taxon, thus rendering the name unusable. This has now been rectificed with a corrigendum, and gaddisi is the type species of Leptorhynchos. This would leave the fate of their referral of Ornithomimus elegans, often placed in Chirostenotes or, more recently, in Elmisaurus, up to more grabs. Which, sadly, is where it belongs. Thus, this removes the uncertainly surrounding the legitimacy of “Leptorhynchos,” and I can now add it to the list of new, valid oviraptorosaurian taxa.
Longrich, N. R., Barnes, K., Clark, S. & Millar, L. 2013. Caenagnathidae from the upper Campanian Aguja Formation of west Texas, and a revision of the Caenagnathinae. Bulletin of the Peabody Museum of Natural History 54 (1): 23-49.
Longrich, N. R., Barnes, K., Clark, S. & Millar, L. 2013. Correction to “Caenagnathidae from the Upper Campanian Aguja Formation of West Texas, and a Revision of the Caenagnathinae.” Bulletin of the Peabody Museum of Natural History 54 (2): 263-264.
In the interests of open sourcing, the following skeletal reconstructions and descriptions are CC-BY. This means they are entirely open-access, and you may do whatever you wish with them so long as you attribute the material to me. You do NOT need to source me when you make a drawing based on them, although linking back to the source and my name is a nice thing.
These illustrations are being prepared for a forthcoming book on dinosaurs of the British Isles, but I retain the rights, and to that I continue my quest to make these freely available. Enjoy.
Posted in Art, Paleontology, Reconstruction
Tagged Cetiosaurus, Dacentrurus, Dinosaurs, England, Eustreptospondylus, Jurassic-Cretaceous Boundary, Ornithischians, Sauropods, Skeletons, Theropods
What? Another All Your Yesterdays mention?
You remember when I asked you all what this might be? Someone got the right answer, although I’d love to speculate how they came about it. I have a clue, and it might be for the sake of perversity, or because I’m a predictable schmo (read: Yiddish, “I’m an idiot”). Continue reading
Not that long ago, Memo Koseman, John Conway, and Darren Naish published a book titled “All Yesterdays,” a volume that encapsulated a philosophy of flexibility in reconstruction of ancient life, and a short perspective on the problems facing modern reconstruction of that like and how modern animals might look under that perspective. We got into the habit of portraying animals like pariesaurs, ichthyosaurs, dinosaurs, and pterosaurs — all your -saurs, really — a particular way, and we weren’t changing much from some general perspectives. This book sought to identify problems with these reconstructions, and hoped to alleviate them by pointing at them and offering up a possible alternative.
Now, I have in the past been somewhat critical of this movement. As a budding anatomist and someone concerned with the biomechanics of an animal, I tend to work from the fundamentals outward, and part of this requires the constraints of the known. Because of this, I tend not to get so overly exaggerated, even in my art. I wrote a post about the book and the paleoartist’s dilemma and the movement towards a more rigorous, realistic, and science-based reconstruction method. In this, I criticized part of the movement as putting too much emphasis on what might be — inductive reasoning — rather than taking what is and applying what we know to it, to eliminate what is unlikely — deductive reasoning. I still feel this is sound philosophy.
Seriously, you get into a blogging funk and get all busy at home life and someone comes along to publish a new oviraptorid from Southern China … as if there weren’t enough of those already to deal with. And as if I didn’t have enough things to do already. It’s called Jiangxisaurus ganzhouensis, is from the same locality as Banji long and purported for Ganzhousaurus nankangensis (though it’s collection by private hands raises doubts on the specifics a little — for more details, read here), and is almost as well preserved as Banji long and nearly as complete. But, much larger. And while that raises the specter of ontogeny, as did Banji long when it first appeared, it is not possible from the paper alone and the one photograph of the skeleton/skull provided (preserved in ventral view and dorsoventrally flattened) to assess this problem. Sigh. Eventually I’ll get around to this if someone else doesn’t first. Till then…
HGM 41 HIII 0421, holotype of Jiangxisaurus ganzhouensis (Wei et al., 2013). Caption for figure from the original. Note: “HGM 41 HIII 0421″ is an attempt at rendering the “normal” specimen number of HGM41HIII0421, which borders on illegibility.
Wei X.-f., Pu H.-y., Xu L., Liu D., & Lü J.-c. 2013. A new oviraptorid dinosaur (Theropoda: Oviraptorosauria) from the Late Cretaceous of Jiangxi Province, Southern China. Acta Geologica Sinica 87 (4): 899-904. [English Edition]
The orientation of the head for standardized anatomical comparison is important for biological and paleontological analysis. It influences anatomical direction, description, the relationship of soft-tissue, study of behaviors such as feeding by the orientation of muscles versus gravity, and so forth. In the past, most researchers have focused on the passive observation of animal posture to determine “static” poses, leaning towards the “at rest” and “alert” or “active” postures, whereby the animal is in a static, but attentive posture. In the 40s, 50s and 60s, several studies of avian, mammalian, crocodilian, and squamate rest/alert postures attempted to find static anatomical features that could translate to fossils for the purpose of finding a “holy grail” of head attitude. Most of this focused on the orientation of the lateral semicircular canal (LSC) relative to the skull. I covered portions of this here and here, and through those links you will find more extensive discussion.
Fig. 1 from Marugán-Lobón et al. (2013), showing basal and LSC-calibrated postures for a human and a stork (Ciconia ciconia).