Episode 372: The axe-tailed ankylosaur


Episode 372 is all about Chindesaurus, Basal saurischian that lived within the Late Triassic in what’s now Arizona.

Massive due to all our patrons! Your assist means a lot to us and retains us going! For those who’re a dinosaur fanatic, be part of our rising group on Patreon at https://www.patreon.com/iknowdino.

You possibly can hearken to our free podcast, with all our episodes, on Apple Podcasts at:
https://itunes.apple.com/us/podcast/i-know-dino/id960976813?mt=2

On this episode, we talk about:

Information:

  • A brand new ankylosaur, Stegouros elengassen, was described with wonderful spikey tail weaponry from Magallanes, Chile supply
  • The brand new sauropod, Rhomaleopakhus turpanensis, was named from the Xinjiang Uygur Autonomous Area, China supply
  • Chief Shikellamy Elementary Faculty in Sunbury, Pennsylvania have a brand new 6 ft Diplodocus femur on show supply

The dinosaur of the day: Chindesaurus

  • Basal saurischian that lived within the Late Triassic in what’s now Arizona, US (perhaps additionally New Mexico and Texas)
  • Seems like a small theropod, strolling on two legs and had an extended tail
  • Kind and solely species is Chindesaurus bryansmalli
  • Discovered a partial skeleton within the Petrified Forest Nationwide Park in 1984 (was airlifted out in 1985)
  • Within the Twenties, Charles Camp from the College of California at Berkeley collected fossils and took photographs of the Petrified Forest. Within the Nineteen Eighties, Robert Lengthy from Berkeley discovered Camp’s websites. Bryan Small, who was on the workforce gathering fossils, discovered the ankle bone of Chindesaurus
  • On the time Chindesaurus was discovered, it was regarded as the oldest dinosaur ever discovered
  • Holotype has a nickname, “Gertie”, after Gertie the Dinosaur
  • Often known as the “Chinde Level dinosaur”, due to the place the specimen was discovered
  • Described in 1995 by R.A. Lengthy and P.A. Murry
  • Genus identify means “ghost lizard” or “lizard from Chinde Level”
  • Genus identify comes from the Navajo phrase chindi, which implies “ghost” or “evil spirit”
  • Species identify is honor of Bryan Small, who discovered the holotype
  • Holotype consists of vertebrae, limb bones, and hip fragments
  • Holotype was ready on the College of California Museum of Paleontology in Berkeley, California
  • Fragmentary skeletons have been present in Arizona, New Mexico, and Texas, however not all of those might belong to Chindesaurus
  • Referred specimens are incomplete and embody vertebrae and femur fragments, though one full femur was present in 2006 in Ghost Ranch, New Mexico
  • Nevertheless, a few of these referred specimens is probably not Chindesaurus, as a result of they don’t have options distinctive to Chindesaurus
  • In 2019, Adam Marsh and others mentioned solely the holotype ought to be thought of to be Chindesaurus
  • A partial lilium present in Texas (Tecovas Formation) was regarded as Chindesaurus after which in 1998, Hunt and others named it as a brand new taxon, Caseosaurus crosbyensis
  • Nevertheless, in 2004 Langer mentioned these two had been the identical species, and Nesbitt and others supported the concept in 2007, saying what made Caseosaurus and Chindesaurus totally different was simply variation in dimension (however they didn’t formally synonmize the 2, as a result of the ilium of Chindesaurus is simply too fragmentary)
  • In 2018 Baron and Williams redescribed Caseosaurus and located it to be legitimate
  • Holotype of Chindesaurus is probably not an grownup, based mostly on an unfused ankle
  • Lengthy and Murry estimated Chindesaurus to be 9.9 to 13.1 ft (3 to 4 m), and to have a stout physique, lengthy legs, and an extended neck
  • In 2012, Benson and Brusatte estimated Chindesaurus to be 6.6 to 7.5 ft (2 to 2.3 m) lengthy
  • Additionally in 2012, Holtz estimated Chindesaurus to be about 6.6 ft (2 m) lengthy and weigh about 50 to 100 lb (23 to 45 kg), or about the identical as a wolf
  • No cranium has been discovered
  • Had giant tail vertebrae on the base that obtained longer in direction of the tip of the tail
  • Had lengthy, low cervical vertebrae, so neck was in all probability gentle and slender
  • Had a big, crescent-shaped femur
  • Numerous debate over what sort of dinosaur Chindesaurus was. At occasions regarded as a basal sauropodomorph, then later regarded as a herrerasaurid
  • In 2007, Nesbitt and others and Irmis and others advised Chindesaurus was a basal saurischian
  • A phylogenetic evaluation discovered Chindesaurus to be a sister taxon to Tawa hallae (beforehand Chindesaurus was regarded as a herrerasaurid and Tawa a theropod). Chindesaurus and Tawa had been positioned inside basal Saurischia, earlier than sauropodomorphs and theropods cut up off
  • In 2019 Adam Marsh and others redescribed Chindesaurus and located Chindesaurus and Tawa to be “a probably numerous group of early theropods previous to the end-Triassic mass extinction”
  • In 2019, Morgan Schaller and others, researchers from the Rensselaer Polytechnic Institute and College of Texas Austin, discovered that oxygen ranges quickly elevated over a 3 million 12 months interval across the time Chindesaurus lived
  • They analyzed small quantities of fuel from rocks from the Colorado Plateau and the Newark Basin (about 621 mi or 1,000 km away from one another on Pangea and close to the equator), which had been round 215 million years outdated
  • Discovered that oxygen ranges went from 15% to 19% and there was a drop in carbon dioxide ranges (as we speak we now have 21% oxygen)
  • In all probability was a worldwide change in oxygen ranges
  • Across the oxygen peak is when a few of the first dinosaurs appeared within the tropics of what’s now North America, like Chindesaurus (although dinosaurs had been in what’s now South America earlier, about 232 million years in the past). Sauropods got here quickly after
  • Greater oxygen ranges might have helped animals develop bigger
  • On the very least, the environmental modifications had been good for evolutionary diversification, although there might have been different elements that helped
  • Chindesaurus lived on an historic floodplain
  • Different animals that lived across the similar time and place embody archosaurs, pseudosuchians, tetrapods, phytosaurus, Coelophysis, lungfish, and clams
  • A brief documentary, about half-hour, was made about Chindesaurus in 1988, known as “A Whopping Small Dinosaur.” In regards to the expedition and meeting of Chindesaurus

Enjoyable Truth:
Stegouros is the one named dinosaur from Magallanes, Chile and the southernmost of any dinosaur (excluding Antarctica).

Sponsors:

This episode is delivered to you by our patrons. We simply launched our second bonus episode protecting many extra paleontological discoveries for all of our patrons. Head to Patreon.com/iknowdino to get entry and assist us maintain making the present.

For a restricted time if you happen to be part of our Patreon at our Spinosaurus tier you’ll get a steel print of Sabrina’s Oryctodromeus burrow. Go to Patreon.com/iknowdino to enroll and assist us maintain creating I Know Dino each week.



Leave a Reply

Your email address will not be published. Required fields are marked *