Episode 516: A New Stegosaur with Oddly Formed Ft!. The stegosaur Angustungui has claws much like Scelidosaurus regardless of being over 30 million years more moderen. Plus a number of new non-fiction dinosaur books that we’ve been studying recently.
Information:
- There’s a brand new stegosaur, Angustungui qiketaiensis supply
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The dinosaur of the day: Thescelosaurus
- Neornithischian that lived within the Late Cretaceous in what’s now North America
- Neornithischians wore their enamel down erratically from chewing and developed sharp ridges, so they might break down robust plant meals
- One of many final dinosaurs earlier than non-avian dinosaurs went extinct
- Walked on two legs, had an extended tail, quick arms
- Tail had ossified tendons, so tail wasn’t that versatile
- Had sturdy legs, small, huge arms, had an extended head with a pointed snout
- Thescelosaurus neglectus is larger than different basal neornithischians, that are about 1 to 2 m lengthy (over 3 to six.5 ft)
- Skeleton is fairly well-known
- Estimated to develop between 8.2 to 13.1 ft (2.5 to 4 m) lengthy
- Closely constructed
- Estimated to weigh about 450 to 660 lb (200 to 300 kg)
- Had a broad rib cage (and subsequently huge again)
- Had giant, skinny, flat mineralized plates that had been discovered subsequent to the perimeters of the ribs. Unclear what they had been for. Doable they began as cartilage and have become bone because the animal grew up
- Had sturdy limbs
- Leg bones described as like golf equipment
- In all probability not too quick, primarily based on its heavy construct and legs, the place the higher leg was longer than the shin
- Had 4 toes on its ft
- Had hoof-like toe suggestions
- Had 5 fingers on every hand that had been quick and broad
- Had lengthy rod-like bones over the eyes, so seemed prefer it had heavy bony eyebrows
- In all probability herbivorous
- Had an extended, slim beak
- Had small pointed enamel on the tip of the snout and leaf-shaped cheek enamel
- Had a ridge alongside its higher jaws (the tooth-bearing “cheek” bones) and a ridge on each decrease jaws, which can imply it had muscular cheeks
- In 2022, Michael Hudgins and others studied Thescelosaurus enamel and located they differed in dimension, shapes, ornamentations, denticulation, and put on patterns
- This, together with having a slim beak, might imply Thescelosaurus was a selective feeder
- In all probability browsed near the bottom
- Skeleton referred to as “Willo” was described in 2000 as having a four-chambered coronary heart and aorta (specimen on show on the North Carolina Museum of Pure Sciences)
- Fossils present in 1993 in South Dakota
- Scientists did CT scans and recommended the guts turned to cleaning soap as a result of it was buried in airless circumstances after which fossilized and turned to goethite, an iron mineral. Additionally discovered Thescelosaurus had an elevated metabolic price (heat blooded)
- Authors recommended the guts was much like that of an ostrich with 4 chambers
- A 2001 paper by Timothy Rowe and others discovered the guts was a concretion that constructed up an additional dense a part of sedimentary rock
- The specimen was discovered within the Hell Creek Formation in fluvial settings, which don’t normally protect gentle tissues (rivers and streams), and the group discovered it unlikely a dinosaur coronary heart may fossilize in these circumstances earlier than micro organism consumed it. Additionally stated, “Ironstone concretions are infamous for producing suggestive and deceptive shapes” and on this case, the shapes and positions weren’t proper
- Discovered that issues just like the “aorta” lacked arteries coming from it, and argued one other concretion was preserved behind the best leg
- Unique authors agreed it was a concretion however stated it shaped round and partially preserved elements of the guts
- A 2011 research by Timothy Cleland and others did CT scans, histology, x-rays, and extra and located the article was a concretion of sand from the burial setting and never a coronary heart, although there may be remoted areas of tissues preserved
- Discovered that the guts didn’t have 4 chambers and as a substitute had three areas that had been unconnected, so couldn’t be a coronary heart (must be related for blood to circulate by means of)
- Thescelosaurus makes an look in “Dinosaurs: The Closing Day with Sir David Attenborough”
- Exhibits a Thescelosaurus leg discovered on the Tanis web site
- Paul Barrett stated the leg has pores and skin impressions that present it was scaly, and that there’s no proof of illness or pathologies or being scavenged (chew marks) so appears the leg was ripped off rapidly and the dinosaur died virtually immediately
- Doable it died the day the asteroid hit Earth
- Not all paleontologists agree
- Doable that some animals died earlier than the asteroid hit after which acquired ripped aside the day it hit and buried in a approach that makes it appear it died from the asteroid
- Speak at size concerning the Finish Cretaceous extinction in our upcoming I Know Paleo mass extinction saga
- In 2014, Clint Boyd described the cranium of Thescelosaurus neglectus
- Cranium not identified in any respect till Thescelosaurus edmontonensis was synonymized with Thescelosaurus neglectus in 1974 by Peter Galton
- In episode 492, we talked concerning the research earlier this yr by David Button and Lindsay Zanno, the place they made a 3D mannequin of the within of the mind of Thescelosaurus (the “Willo” specimen) and located it had a strong sense of odor, a delicate vestibular system, however horrible listening to—all which can imply it was a burrower
- Mind was common or beneath common for its physique dimension
- However its olfactory bulbs, which assist with sense of odor, make up about 3% of the endocast quantity (bigger than trendy birds and much like trendy rabbits and pikas)
- Used odor to assist discover meals. Odor would assist it keep away from predators, and establish its household and younger underground
- Snout may root round in dust
- Had highly effective arms, which can have helped it dig holes
- Had a delicate vestibular system, a comparatively small mind, not nice of listening to, however an awesome sense of odor, which is all good for burrowing
- No preserved burrows, like Oryctodromeus. However possibly spent a while underground and a while above
- For the listening to, in all probability couldn’t inform the distinction between high and low frequency sounds very properly
- Listening to vary much like some crocodilians and squamates (lizards and snakes), however not so good as different dinosaurs like Dysalotosaurus. May in all probability hear greatest between ~1100 to 1200 Hz (higher restrict of 3051 Hz). For comparability, Dysalotosaurus estimated to have a listening to vary of ~350 to 3850 Hz
- Kind species is Thescelosaurus neglectus
- Genus title means “godlike” or “marvelous” or “wondrous” and “lizard”
- Three species: neglectus, garbanii, and assiniboiensis
- Fossils have been present in Alberta (Scollard Formation) and Saskatchewan (Frenchman Formation) in Canada, and in Wyoming (Lance Formation), South Dakota and Montana (Hell Creek Formation) and Colorado (Laramie Formation) within the U.S.
- Fossils first present in 1891 by John Bell Hatcher and William Utterback, in Wyoming (Lance Formation)
- It wasn’t till 1913 Charles Gilmore discovered it within the collections of the Smithsonian and named it Thescelosaurus neglectus (species title manes “uncared for”)
- Thought it was associated to Camptosaurus on the time
- Charles Gilmore, in 1913 wrote: “the cranium and neck being the one essential elements lacking”
- In 1915 Gilmore wrote a extra detailed description of the fossil, after it was ready
- Over time, different species assigned to Thescelosaurus however had been later reclassified
- William Morris in 1976 described a specimen with a partial cranium, elements of vertebrae, and finger bones present in South Dakota, U.S. (Hell Creek Formation), as an unidentified species of Thescelosaurus, however Peter Galton later categorised it as Bugenasaura infernalis, which suggests “giant cheeked lizard belonging to the decrease areas”
- Morris additionally named one other specimen ?Thescelosaurus garbanii (wasn’t certain it belonged to the genus), primarily based on a partial leg that was a 3rd bigger than different Thescelosaurus specimens, in addition to neck and again bones, present in Montana, U.S. (Hell Creek Formation))
- Found by Harley Garbani
- Estimated to be about 15 ft (4.5 m) lengthy
- In 2009, Clint Boyd and others discovered Bugenasaura to be a synonym of Thescelosaurus (identical skulls), and located Thescelosaurus garbanii to be legitimate. Additionally discovered there was a doable unnamed third species, primarily based on a specimen with some distinctive options
- In 2011, Caleb Brown and others named the third species, Thescelosaurus assiniboiensis, primarily based on a small, articulated, almost full skeleton present in Saskatchewan (Frenchman Formation)
- Features a cranium, with a braincase
- Species title refers back to the “District of Assiniboia, a regional administrative unit of the North-West Territories, Canada, from 1882 to 1905”, which finally turned Saskatchewan and Alberta. District named after the Assiniboine First Nations Folks
- Discovered Thescelosaurus was one of the vital ample dinosaurs within the Frenchman Formation
- Within the Frenchman Formation, 4 partial skeletons discovered in addition to a number of remoted bones
- Not a dominant dinosaur within the Hell Creek (one research discovered it was possibly 5% of all articulated skeletons within the Hell Creek Formation), in comparison with about 31% within the Frenchman Formation
- Fossils of the small skeleton discovered within the Frenchman Formation in 1968 and articulated
- Is probably not skeletally mature, however nonetheless thought of to be a definite species as a result of it’s solely 13% smaller than Thescelosaurus neglectus and it has distinctive options within the cranium that in all probability wouldn’t change because it grew up
- Bonebed of a number of dinosaurs discovered within the Frenchman Formation, together with remoted limb bones from small Thescelosaurus, which can be from juveniles
- Some juveniles identified, largely from enamel
- Many fossils present in sandstones that characterize channel environments
- Appears to have frequented stream channels, and when it died might have been in or close to rivers, which makes it simpler to bury and fossilize
- Lived in coastal plain environments like swamps and marshes
- Might have lived close to streams
- Different dinosaurs that lived across the identical time and place embrace the ceratopsids Triceratops and Torosaurus, the hadrosaur Edmontosaurus, the ankylosaur Ankylosaurus, the pachycephalosaur Pachycephalosaurus, and theropods together with Ornithomimus, Troodon, and Tyrannosaurus
Enjoyable Reality:
New know-how means researchers can hunt for fossils already in museum collections.
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