Too Many Choices

Probably because Simosuchus has such an interesting skull and teeth for a crocodilian relative there are a number of papers and studies of Simosuchus. The odd shape and the intriguing phylogenetic position of Simosuchus are also often studied topics as well. I know that a number of the readers here have read a lot of these papers, and maybe even know them by heart. The discussions here lately have been quite vibrant and I hope they continue, so if anyone reads these papers and has questions please feel free to ask them. I am sure someone can answer them. Instead of describing each paper and then linking them, I am simply going to link them by subject here. As a fair warning, many of these papers come from a 2010 Memoir edition of the Journal of Vertebrate Paleontology specifically about Simosuchus (read as you may need to look for additional links to read these):

Description paper by Buckley et al (2000)

Phylogeny of Simosuchus by Turner and Sertich (2010)

Craniofacial morphology by Kley et al (2010)

Postcranial skeleton:
Appendicular by Sertich and Groenke (2010)
Axial skeleton by Georgi and Krause (2010)

Osteoderms by Hill (2010)

Well Done Videos

Probably not the group that we would normally turn to here to get facts and videos, the Expeditioner's Discovery Guild is a channel on YouTube that has a lot of wide-ranging videos. One of their videos is the 7:21 second description and artwork compilation addressing Simosuchus. There is a lot of good information here and it is worth watching. It actually directly answers some of questions that people have asked in the last 24 hours as well.

Pug-o-dile

The pug nosed crocodile, Simosuchus clarki (Buckley et al. 2000) is named for its short and blunt snout. Recovered from the Mahajanga Province of Madagascar, the small (2.5 ft; 0.75 m) crocodylomorph had small leaf shaped teeth and is thought to have been one of a number of early suchians that was actually herbivorous rather than carnivorous. There are quite a few interesting facts about this suchian and its lifestyle that tell us a lot about the evolution of crocodiles. Stick with us to see tomorrow what kinds of interesting facts we will share tomorrow.

Photo of ROM display specimen by D. Gordon E. Robertson

Pseudosuchian Archosaurs

Rather than spend today telling the intrepid readers (and viewers of videos) what a pseudosuchian is and is not, I present to you today videos that show, describe, and discuss Revueltosaurus.The genus Revueltosaurus consists of three recognized species: R. callenderi Hunt, 1989 type; R. olseni Hunt and Lucas, 1994; R. hunti Heckert, 2002. The first video comes from Petrified Forest and the National Park Service. It describes the finds at the park and where some of those bones come from on the skull of this crocodile relative. The second video features NMMNH Chief Scientist Spencer Lucas talking about what exactly Revueltosaurus is and is not, in a very short manner of time (the clip lasts approximately 90 seconds).

Daspletosaurus Appears on Television

Daspletosaurus was an interesting tyrannosaurid for a number of reasons. One of the reasons that has been explored was that Daspletosaurus was contemporaneous with another tyrannosaurid, Gorgosaurus libratus. The BBC show Planet Dinosaur was willing to imagine the world in which these two gargantuan dinosaurs lived, how Daspletosaurus may have hunted its prey, and how Daspletosaurus and Gorgosaurus may have interacted. The clip below only shows Daspletosaurus hunting and fighting with a Centrosaurus however.

Facts and Cartoons

I'm A Dinosaur did a little bit less packing in of the facts on Daspletosaurus than they typically do, however it is still entertaining and has some facts for everyone.

The facts are well represented today though. If one chooses to read, you could visit ThoughtCo, the BBC, and even Enchanted Learning (if you want a very quick sheet of facts that are kid-friendly). A more in depth discussion of facts is also available in the I Know Dino podcast's Dino of the Day. This is available on YouTube:

The Frightful Lizard

The "Frightful Lizard", Daspletosaurus consists of two recognized species: D. torosus Russell 1970 and D. horneri Carr et al. 2017. Daspletosaurus was at the top of its game during the Late  Cretaceous approximately 77 to 74 million years ago. Fossils of Daspletosaurus have been found in Alberta (D. torosus) and Montana (D. horneri) and are contemporaneous with Gorgosaurus, Centrasaurus, Hypacrosaurus, Brachylophosaurus, and Albertaceratops, among others. It is hypothesized that Gorgosaurus and Daspletosaurus may not have been in direct competition as apex predators, allowing for some niche partitioning that enabled them to live in the same areas at the same time without out-competing one another. As the more robust of the two genera, Daspletosaurus may have been more likely to prey on the more physically robust and difficult to take down ceratopsians than hadrosaurs; leaving hadrosaurs for lean times and Gorgosaurus.

©Dmitry Bogdanov

Different -aroo

The kangaroos now exists as two species in one genus in Australia (and outside too as zoo animals and, increasingly, as pets). However, like any living animal, the kangaroos have ancestors, and a lot of them were very interesting. There have been kangaroos that walked instead of hopping and there have been kangaroos with rather large fangs. Most of those kangaroo ancestors have a -roo ending, which makes for some interesting names as well. One of the newest of these animals is the first true kangaroo known from 23 million years ago. This kangaroo, Cookeroo (divided into two species: C. bulwidarri and C. hortusensis), is also thought to have walked and scurried rather than hopped across the Australian landscape. These hypotheses are based mainly off of phylogenetic position (based on what I have found), as the paper describing the fossils describes numerous skulls, which are mostly incomplete, though some are fairly complete.

Holotype of Cookeroo bulwidarriPhoto posted by Dr. Kaylene Butler

I Forgot Yesterday

Yesterday I had a video with Jeffrey Wilson all lined up and then I forgot to post it. So therefore, here today is Dr. Wilson talking about the large sauropod eating snake Sanajeh. He is seated next to a sculpture of the fossil which, in my opinion, is pretty fantastic. The fact that the fossil itself depicted this scene is one of the fascinating things about paleontology. Not only do we sometimes find new animals in fossil deposits, but sometimes, such as with Sanajeh, we get to see a scene of nature's beauty and ferocity frozen in time forever. Enjoy the video:

Dinosaur Train Facts

Dinosaur Train delivered facts are always a nice short video full of facts that we can rely on. If that video is not enough there is also the ThoughtCo fact page.

Snakes and Fossils

In 2010 Jeffrey Wilson and colleagues described a fossil snake found in the Western Indian state of Gujarat outside the village of Dholi Dungri. That snake is known as "Ancient Gape" or, in Sanskrit, Sanajeh indicus (indicus coming from the Latin meaning from India). The snake was discovered coiled around sauropod eggs, with an additional 50 cm long sauropod body found nearby. This Late Cretaceous snake, a Madtsoiid or Gondwanan clade snake, is thought to have regularly preyed on sauropods because of this discovery. Vertebrae, ribs, and a very rare but very fortunate nearly complete cranium including the lower jaw were discovered in this fossil. In extant snakes the head is extremely loosely connected together, as it was in Sanajeh. Even now these modern snakes are rarely found intact because of these loose connections. The fact that Sanajeh was discovered with a nearly complete skull and jaws is remarkable, and, as we can see in the line drawing of the fossil, uncovering this find must have been fairly fantastic.

From Wilson et al., 2010

Imagery

The majority of posts lately have been the kind of posts I can do with minimal research, you may have noticed. This is because I am doing a lot more work in my personal life and career than I had been doing previously. That sounds like I was lazy before, but that's not what I intended. At any rate, you can continue to expect a number of posts a week still, which is why we all visit the page to begin with. Today, for example, the simple posting you see here is one of the more interesting images of this small ornithischian ball of feathers. All of the artistic impressions of Kulindadromeus appear to have taken the feathering to an extreme such that the dinosaur looks less like a dinosaur than it does a small chicken or duck chick. My favorite version of these fluffy versions of Kulindadromeus is Jed Taylor's watercolor-esque duo which he posted on Twitter. These two are less fluffed than other versions and there is a somewhat abrupt appearing end of the feathers at the base of the tail. If you have a favorite share them in the comments below.

©Jed Taylor

More Popular Movies

Yesterday I posted some fact videos. Today, there are some informational videos that tell you about reconstructing the dinosaur and the feather structures that were discovered in the fossil material.

A Runner in Motion

On this beautiful, but very hot, Sunday, watch some nice fact videos and a slideshow of scientific illustrations of Kulindadromeus. Do not let my short entry here belittle the facts on these videos:

I Know Dino:

WizScience:

"Tribute" video:

All Feathered

Kulindadromeus zabaikalicus (Runner of Kulinda + the Russian subject of Zabaykalsky Krai) was a Jurassic ornithischian, an herbivore, and was found in Russia and described in 2014 by Godefroit et al. These are all rather uninteresting facts; however, Kulindadromeus is a very important dinosaur. This dinosaur was discovered with traces of its integument evident with the fossil. That integument is consistent with the structure of protofeathers that have been discovered in a number of Coelurosaurian dinosaurs, early birds, and dromaeosaurs. The discovery of feathers in a non-avian line dinosaur indicates that the protofeather may have been a characteristic that was basal to all dinosaurs and not just the dinosaur family tree that eventually took flight.

©Nobu Tamura

Living Relatives

The Chacoan peccary (Catagonus wagneri) of Paraguay, Bolivia, and Argentina numbers approximately 3,000 animals remaining in the wild. This is important for a number of reasons, but the most important reason for us today is that, as the closest remaining descendant (hypothesized) of Platygonus, it is a stand in for our fossil peccary. Though smaller than its extinct ancestor genus Platygonus, Catagonus shares an interesting part of its known history with Platygonus. The Chacoan peccary was initially described as an extinct animal of South American in 1930. It was not until 1971 that living examples of the peccary were found by non-native scientists. The native people of Argentina showed the animals, which they called tagua, to biologists that were in the area. This video shows images of the tagua or Chacoan peccary, which stands in for its ancestor Platygonus.

New Week

I intended to discuss the book Unnatural Selection more than I was able to last week, but I received an email that has kept me fairly bust since last Monday or Tuesday. Instead of spending multiple weeks on the book, I thought that this week we could di○scuss a fossil ancestor of one of the animals that is highly important to discussions in the book about selective breeding. We have discussed the origins of cats and dogs a number of times here and we have also discussed more than a few early birds, their cousins, and their ancestors. The remaining group that I had mentioned from the book is that lovable farm (and table group), the pigs (a magical animal, as regards the table comment).

Suidae consists of a large group of animals, both domesticated and feral, today. At one point we tried to discuss the origin of pigs, but they are a diverse group of animals that have evolved into 17 species across 6 genera and a wide variety of sizes and diets. Also, it was a two entry week, because I was extremely busy, in which we discussed Strozzi's Pig (Sus strozzi). The story of the evolution of the domesticated pig begins with the wild boar (Sus scrofa) and Strozzi's pig is a step along the road between ancient relative and modern pigs. Part of the reason Strozzi's pig died out is actually tied to surges in the population of S. scrofa. Going farther back on the family tree is somewhat problematic, but entertaining because the clade that all pigs and boars belong to is called Artiofabula which welcomes its own puns. Despite all we know about living pigs and boars and having a general idea about their familial relationships, there is not that much known about the origins of Suiidae itself. However, because we had a brief discussion about S. scrofa and domestication before, we are going to talk this week about an ancestor of the peccaries, rather than the wild boar.

Peccaries of the family Tayassuidae in the group of Suidae are the only pigs native to the Americas. Historically measuring approximately 90 and 130 cm (3.0 and 4.3 ft) in length and about 20 to 40 kg (44 to 88 lb), peccaries are smaller than boars and domesticated pigs. Wild pigs and boars in the United States, for instance, are not peccaries but feral versions of the domesticated pigs that came over with European settlers. One of the most well-known wild suids in the United States, the javelina, is a peccary though. Confusion between feral domesticated pigs and peccaries is very common. Regardless, peccaries have their own rich history in North America. One of the extinct members of the family, Platygonus, consists of 18 described species of ranging from Canada to Mexico and California to Pennsylvania throughout the Pliocene and into the Pleistocene. Platygonus was rather large for a peccary at 1 m (3.3 ft) long. Long legs made it capable of running at a fair speed and tusks allowed it to defend itself from predators. It is thought that these peccaries lived in herds as well, making them a bit more well protected than solitary pig and peccary species.

©Charles R. Knight, Platygonus leptorhinus

Classy Introductions

In order to name something, you need to be able to define the parameters of that thing — to know categorically when it ceases to be one thing and becomes another.

- Page 8, Unnatural Selection 

Every science text that aims to cross over to popular nonfiction work needs to have a very good introduction that not only grabs the reader's attention but also explains the basic tenets of the book's context in a way in which non-scientist readers can follow along and apply the fundamentals of these ideas. Application can be either within the text or outside of the book. Most authors that care about teaching their audience (we hope all authors, of course) spend a great deal of time explaining these basic principles of their text to make this process easier. The first few chapters of Unnatural Selection outline some of the basic principles of evolutionary science including basic lessons in phylogenetics, speciation, and a basic understanding of plasticity.

I did not mention this yesterday, however, Unnatural Selection is a book that focuses primarily on the phenomenon of dometication in its various forms, that is from the development of livestock to pigeon fanciering and from dog breeding to the very complex nature of swine domestication and hybridization. To sum it up more succinctly, the book is about selective breeding, and the basic principles of how we name animals, how they are related, and how this breeding process has worked over time are very important to understanding the later chapters of the book. Therefore, the first section of the book, in which these principles are taught to the reader, are very important. They are, fortunately, very well written.

As an example, the sometimes difficult to explain concept of organismal plasticity is written such that it is fairly easy to follow as well. In the scope of the book (that is in its use in describing selective breeding), a slightly different definition is used than that of the strict biological definition of the word. In that strict biological sense of the word we are looking at a phenotypic plasticity or the adaptability of an organism to changes in its environment. Unnatural Selection approaches plasticity in terms of the potential for changes over generations, rather than in a single generation. We could say the difference is that between an animal that experiences an environmental change over its life (for a myriad list of reasons hypothetical or otherwise) compared to the changes of a dog (cat, pig, pigeon, parakeet) breed over successive generations (see below for change over time in Bullterrier skulls). That breed can change in many different ways for a variety of reasons including, as van Grouw says, "fashions might simply change." Additionally, because these animals are all interbreeding subspecies, those plastic changes can flip, flop, and twist in amazingly interesting ways over the years because of the breeding of mutts and mixes of purebreeds that become fashionable (think of things like Labradoodles).

©Katrina van Grouw

Skeletons and Popular Literature

A few years ago a book was written called The Unfeathered Bird that was focused on the anatomy of birds, showing birds as they are not often seen in popular literature. The illustrations for the book were hand-drawn skeletal, muscle, and even some feathered images of a wide array of birds, highlighting differences and similarities across a wide range of birds; hitting every bird in this manner would be a life's work and well beyond the scope of a single book. A follow-up work by the author and illustrator Katrina van Grouw was recently published titled Unnatural Selection. Though not a follow-up in the sense of focusing on birds, Unnatural Selection does continue as an investigation of evolution, anatomy, and high quality illustration of a wide range of animals. Over the next week I am going to go over some of the chapters of the book. We will also get to see some of the illustrations that grace the pages of the book.

We can get back to fossil animals next week.

Fame and Mice

As we have stated this week, Mussaurus is well-known among paleontologists and it is actually fairly well-known by the public as well. This is partly because of its bogus claim of being the smallest dinosaur; granted it was the smallest known dinosaur when originally discovered and the hatchlings and juveniles are still quite small for dinosaurs. The sheer number of websites with information, images, and videos of Mussaurus attests to the dinosaur's popularity. If that was not enough, there is also an electronic toy version of the dinosaur and, back after not seeing one of these information trading cards in a long time, Mussaurus is featured below, looking very angry for some reason.