For a primer on this blog series and an FAQ see here.
| Other Episodes |
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| Coasts | Deserts | Freshwater | Ice Worlds | Forests |
| Islands | Badlands | Swamps | Oceans | North America |
This episode features contributions from the following paleontology consultants:
Continue reading Post ID 21950
For a primer on this blog series and an FAQ see here.
| Other Episodes |
||||
| Coasts | Deserts | Freshwater | Ice Worlds | Forests |
| Islands | Badlands | Swamps | Oceans | North America |
This episode features advisement by the following paleontology consultants:
This episode is easily the most fanciful in its interpretations. It pushes a modern-day paleontology myth about a highly temperate Mesozoic that is worthy of a blog post all of its own. I’m keeping things tight here for the sake of the sin theme, but I’ll likely revisit this topic again in the future.
Continue reading Post ID 21950
For a primer on this blog series and an FAQ, see here.
| Other Episodes |
||||
| Coasts | Deserts | Freshwater | Ice Worlds | Forests |
| Islands | Badlands | Swamps | Oceans | North America |
This episode features advisement by the following paleontology consultants:
Continue reading Post ID 21950
For a primer on this blog series and an FAQ, see here.
| Other Episodes |
||||
| Coasts | Deserts | Freshwater | Ice Worlds | Forests |
| Islands | Badlands | Swamps | Oceans | North America |
This episode features advisement by the following paleontology consultants:
Continue reading Post ID 21950
For a primer on this blog series and an FAQ, see here.
| Other Episodes |
||||
| Coasts | Deserts | Freshwater | Ice Worlds | Forests |
| Islands | Badlands | Swamps | Oceans | North America |
This episode features advisement by the following paleontology consultants:
Continue reading Post ID 21950
This has been an idea that I toyed around with ever since the original marketing push for the show. It was clear to me then that the show was going to portray a very distinct narrative regarding dinosaur paleobiology and paleoecology. When the series originally came out I watched it, took my notes and then sat on it. I did this in part because I knew that most people would view the criticism as petty whining or complaints about dinosaurs not looking the way that “I” think they should, or any of the other complaints I received the last time I shot down these “documentaries”. So I let it go.
The first season of Prehistoric Planet came and went with a bunch of fanfare from the paleophile crowd but very little movement on the pop culture barometer (being shackled to Apple TV+ really limits the reach of the series). No harm no foul. Except that to date no one has really tackled the myriad problems with the show’s factual accuracy. As far as internet history is concerned, Prehistoric Planet is a resounding success for paleontology and science communication.
Then “season 2” came out to a similar amount of hype. I was intending to release this post during then but sat on it again. This time was because I got too busy IRL. Now, here we are some two years after the original came out and with us on the cusp of a new Walking with Dinosaurs series, I’m finally publishing this.
This post is the first of an 11-part series done in the style of the CinemaSins YouTube series. Each installment covers an episode. This installment covers the MLQs or Most Likely Questions (can’t be an FAQ if no one has asked it yet). The goal is to cut off some of the most common questions before I (inevitably) see them in the comments.
Continue reading Post ID 21950
[Editors note: See update on the archive below]
In the field of vertebrate paleontology and associated paleophilia, the Dinosaur Mailing List (DML) was an invaluable source of information and networking opportunities. For many—including myself—the DML was a formative experience.
Started back in late 1993/1994 at the University of Pennsylvania, the list initially ran internally with individuals on the list exchanging e-mails back and forth. Then, a few months later, the Cleveland Museum of Natural History agreed to host an archive of these e-mails, creating the now venerable Dinosaur Mailing List Archive. In its heyday, the DML would readily see an influx of more than 100 e-mails a day, covering everything from pack-hunting in theropods to the latest buzz on yet to be published fossils.
Sadly, over the years and with the rise of social media, the list has fallen into disarray with fewer practicing paleontologists (and people in general) using it. As of this writing the DML sees a handful (1–5) e-mails a day with almost all of them being links to recently released papers and associated news articles (courtesy of the ever diligent Ben Creisler). While the present version of the list is but a shell of its former self it is the immense history of the archive that matters. 27 years of correspondence from various paleontologists throwing around ideas and challenging hypotheses. More than just offering a fascinating glimpse into the past, the DML archive has proven influential enough to even get cited in publication (e.g., Witton and Habib 2010).
Unfortunately, earlier this year the Dinosaur Mailing List suddenly disappeared from its former location (dml.cmnh.org). Their host, the Cleveland Museum of Natural History, could no longer afford to maintain the archive on the site, forcing it to shut down. DML owner and listserv moderator, Mickey Rowe, attempted to find another host but to no avail. Thus, in late summer 2021 the DML archive officially disappeared from the internet.
Thankfully, through diligent efforts from Nick Gardner and others, a copy of the archive, prior to shutdown, was obtained from Rowe and distributed freely to anyone willing to host the archives. The hope is that with enough redundant backups out there the archive should never disappear again.
So, I’m doing my part. The DML Archives from April 1994 to May 2021 can now be accessed on the Reptipage.
The new archive link can be accessed here: https://reptilis.net/DML/dinosaur.html
You will also find a menu link at the top of the blog.
We are still waiting to see where the new archive of the DML will land (for now, no e-mails are being archived). Hopefully, the DML will continue to find a home somewhere. If not, and this is the end of an era, this mirror will be one of the many headstones for this once illustrious interaction of amateurs and professionals.
Major Update: The University of Southern California has picked up the mantle and started archiving new messages from the DML.
https://mymaillists.usc.edu/sympa/info/dinosaur-l
However, one must be a member of the Dinosaur Mailing List to access the archive.
Thanks to Mary Kirkaldy and Ben Creisler for the following information on how to properly get access to the new DML archive (see instructions below).
To join the DML, you will first need to send a message to sympa@mymaillists.usc.edu from the address that you want to use to subscribe to the list.
In the subject line, put: subscribe dinosaur-l First Name Last Name.
Change “First Name Last Name” to your name or the name you want to use.
Subscription is free.
The next step is to access information about your subscription to the dinosaur mailing list. Go to: https://mymaillists.usc.edu/sympa
The first time you visit the site, click on: “First login?” at the upper left of the page.
Enter your e-mail address and click the “Request first password” button. The site will e-mail you a message with a link.
Clicking that link will take you back to the site with a page asking you to enter a password twice.
Once you are logged in, any lists you are subscribed to will appear in a pane on the left. Click on “dinosaur-l” to access your subscription options.
You can also type “dinosaur” in the Search List on the left. It should bring up the DML main page. From there, click on Archive on the left. It should open and allow you to choose a month.
If you would like to learn about your subscription options and how to change them, click the “help” tab near the top right. If you are set to digest mode, note that it is in MIME format for the digests. There is an option for plain text if you don’t like the MIME format. The list is configured to send out a reminder once every two months.
This isn’t as easily accessed as it was in the past, but it’s a heck of a lot better than no archiving at all.
~Jura
This week saw the release of a new paper that has implications for dinosaur metabolism.
Dawson, R.R., Field, D.J., Hull, P.M., Zelenitsky, D.K., Therrien, F., Affek, H.P. 2020. Eggshell Geochemistry Reveals Ancestral Metabolic Thermoregulation in Dinosauria. Sci. Adv. 6:eaax9361. (Open Access)
The paper makes some pretty hefty claims regarding dinosaur metabolism, and as such, has received a fair share of media coverage touting this as the latest evidence for “warm-blooded” (i.e., automatic endothermic) dinosaurs.
Every time there is a major headline like that, I feel obliged to go back to the source to see what the media has likely overblown. In this case, media claims don’t seem that far off what was written in the actual paper, which is not necessarily good. Some of these claims do extend beyond the reach of the available evidence (e.g., there actually is no comparison with other contemporaneous reptiles of the region, weakening any arguments for metabolic thermoregulation).
It’s been an age since I’ve done one of these paper breakdowns, but I think this one warrants a more thorough analysis, especially given the implications of the interpretations.
Continue reading Post ID 21950
[NOTE: Post has been updated to include a section on scale size]
This has certainly been an interesting year. Two papers dropped in the past three months that have put the brakes on a recent trend in paleo-art. That trend? Why the feather-coated T. rex of course.
First, in March, we saw the release of a paper detailing a new species of Daspletosaurus and its relationship to D. torosus.
Carr, T.D., Varricchio, D.J., Sedlmayr, J.C., Roberts, E.M., Moore, J.R. 2017. New Tyrannosaur with Evidence for Anagenesis and Crocodile-Like Facial Sensory System. Scientific Reports. 7(44942):1–11.
In this paper, Carr et al. argue for the designation of a new Daspletosaurus species, D. horneri. The authors argue, based on skull shape and chronostratigraphic position, that D. horneri was the direct ancestor to D. torosus. I thought that the authors put forth a compelling argument for this anagenic event and backed up their position well. Interestingly, this part of the paper should have been the most controversial. As anyone who has read anything from Horner and Scanella over the past eight years can attest, arguing for a direct ancestor-descendant relationship for dinosaurs is difficult to do and even harder to win over others in the field. So it is somewhat surprising to see a case for anagenesis in Daspletosaurus taken so well by the palontological community. All the more so given that it involves a tyrannosaur, the poster children for “cool guy” dinosaurs.
Instead, the most controversial part of the paper wound up being their soft-tissue reconstruction of the face for D. horneri. The author responsible for the soft-tissue reconstruction was Jayc Sedlmayr of Louisiana State University. Sedlmayr did his doctorate on osteological correlates for vasculature in extant archosaurs (birds & crocs). He is the seminal alumnus of the WitmerLab and thus is well within his wheelhouse for this type of soft-tissue reconstruction. Sedlmayr borrowed heavily from the work of another WitmerLab alumnus, Tobin Hieronymus, whose PhD work involved osteological correlates for integument on the skulls of animals. Although the skin is often well away from the underlying bones on most of the body, there are exceptions when it comes to the skull. There, areas that are not heavily muscled, tend to show intimate connections between the skin and the underlying bone. Hieronymus used these connections to determine how different integumentary appendages (scales, hair, feathers) affect the underlying bone (Hieronymus & Witmer 2007; Hieronymus et al. 2009). The authors found that the surface texture along the skull of D. horneri was “hummocky”. That is, it was covered in lots of closely packed ridges. According to Hieronymus & Witmer (2007), this texture correlates to scales as the overlying integumentary appendage. Thus, according to the authors, D. horneri had a scaly face (this is grossly oversimplified as the authors were able to piece together a variety of different integument variants along the skull, but you get the idea).
Scaly tyrannosaur cannonball one had been shot.
Then two weeks ago, we saw the release of another paper on tyrannosaur integument. However, unlike the previous paper, this one was specifically dedicated to integumentary types in tyrannosaurids.
Bell, P.R., Campione, N.E., Persons, W.S., Currie, P.J., Larson, P.L., Tanke, D.H., Bakker, R.T. 2017. Tyrannosauroid Integument Reveals Conflicting Patterns of Gigantism and Feather Evolution. Biology Letters. 13:20170092
In this paper, the authors set out to survey all known instances of “skin” impressions for tyrannosaurids. Their list of taxa included Albertosaurus, Tarbosaurus, Daspletosaurus, and Gorgosaurus. Their results pretty definitively indicated that scales were the predominant integumentary appendage on tyrannosaurids. The authors then went on to speculate why that would be if earlier tyrannosauroids had filamentous integument. They performed an ancestral character state reconstruction based on Parsimony and Bayesian-based trees from Brussatte and Carr 2016. Their results found that filaments came out strongly as the ancestral character for tyrannosauroids, but by no later than Tyrannosauridae proper, a reversion to scales had taken effect. The authors attributed this to body size evolution. Namely, larger tyrannosauroids reverted to scales over protofeathers.
Cannonball number 2 had just been shot.
Continue reading Post ID 21950
Most folks who visit my site by now have seen the big dinosaur news that has hit the interwebs. A new study from Matthew Baron, David Norman and Paul Barrett from University of Cambridge and the Natural History Museum of London, has seriously challenged the classic interpretation of dinosaur phylogeny.
Although originally thought of as two unrelated branches of Reptilia that grew to immense size during the Mesozoic (e.g., Charig et al. 1965), for the last 43 years the group, Dinosauria, has been considered monophyletic (i.e., sharing a single origin) with the subgroups, Saurischia & Ornithischia, forming the first major branches within the group (Bakker et al. 1974). Saurischians, or “reptile hips” were aligned together by their similar hip shapes, skull characters (e.g., open antorbital fenestrae), and inferred soft tissues (e.g., air sacs). Ornithischians, or “bird hips” shared a hip structure that was superficially similar to that of birds, with a pubis that pointed caudally rather than rostrally, along with a variety of unique skull characters such as a neomorphic bone known as the predentary.
Study after study showed that this relationship was sound, and so it stayed that way. The problem with getting the same answer over and over again is that one eventually stops questioning it. Consistent results become common knowledge, and may even graduate to dogma. That’s not so bad if that common knowledge is true, but all too often many of these “obvious” cases wind up being just so stories upon closer inspection.
Continue reading Post ID 21950
