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Episode 299: A uncommon Jurassic carcharodontosaur


    Episode 299 is all about Sinosauropteryx, One of many first identified feathered dinosaurs, identified for its lengthy banded tail.

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    On this episode, we focus on:


    • A brand new carcharodontosaur, Lusovenator, was named in Portugal supply
    • A brand new evaluation dates the Carnian Pluvial Episode to 234 million years in the past supply
    • Universiti Malaysia Kelantan just lately discovered dinosaur footprints in Bukit Panau supply
    • There’s a approach to hack the hidden Google Chrome dinosaur recreation to make your T. rex invincible supply

    The dinosaur of the day: Sinosauropteryx

    • Compsognathid that lived in Early Cretaceous in what’s now Liaoning Province, China (Yixian Formation)
    • Small, longest specimen discovered was about 3.5 ft (1.07 m) lengthy, and weighed about 1.2 lb (0.5 kg)
    • Holotype was solely 27 in (68 cm) lengthy, however was a juvenile
    • Bipedal, and had brief arms, giant claws on its first fingers, and an extended tail
    • Had 64 vertebrae within the tail, the longest tail relative to the physique size of any identified theropod
    • Tail helped it steadiness whereas it ran
    • Had lengthy legs
    • Arms have been about 30% the size of the legs
    • Palms have been lengthy in comparison with the arms
    • Had three fingers on every hand
    • Had a excessive cranium
    • Much like Compsognathus
    • Kind and solely species: Sinosauropteryx prima
    • Genus title means “Chinese language reptilian wing”
    • Species means “first” and refers back to the truth it’s the primary, feathered, non-avian dinosaur discovered
    • The unique description of Sinosauropteryx discovered that this dinosaur “upsets and supersedes the over 100 yr standing of Archaeopteryx because the ancestor to birds,” and that it reveals Ostrom’s proposal that theropods became birds
    • Described in 1996 by Ji and Ji
    • First dinosaur outdoors of Avialae to be discovered with proof of feathers
    • Not intently associated to Archaeopteryx
    • Distantly associated to Aves, so not a chook
    • Found in 1996 by Li Yuman, a farmer and fossil hunter
    • Fossils have been in two slabs, and he offered them to 2 museums: Nationwide Geological Museum in Beijing, and the Nanjing Institute of Geology and Paleontology
    • It was an enormous discover, and bought many scientists and artists excited, together with Phil Currie, Michael Skrepnick, John Ostrom
    • Three specimens have been discovered and described and assigned to Sinosauropteryx
    • One of many specimens could also be a brand new species or perhaps a new genus, however hasn’t been formally named
    • Carnivorous
    • Ate bugs and small mammals
    • Had heterodont enamel, with enamel on the higher jaws have been slender and never serrated, and enamel behind them on the maxillae have been serrated
    • One specimen discovered with lizard intestine contents, probably Dalinghosaurus, a quick runner. Additionally discovered small eggs within the stomach, although they have been within the incorrect a part of the physique for the egg shells to remain intact, so probably that they have been unlaid Sinosauropteryx eggs. Eggs have been 1.4 in (36 mm) lengthy and 1 in (26 mm) extensive. Having two eggs could imply Sinosauropteryx had twin oviducts, like different theropods, and laid eggs in pairs
    • One other specimen, the one which may be one other species or genus, was discovered with mammal jaws in its intestine area, together with the jaws of Zhangheotherium, a venomous mammal (had tarsal spurs, spurs on the toes, just like trendy platypus, which additionally produced venom)
    • First non-avian dinosaur discovered with feather-like constructions
    • Had easy, filament-like feathers
    • Feathers are brief, small, and uniform
    • Primitive feathers have been as much as 1.2 in (3 cm) lengthy
    • Couldn’t fly, however feathers could have been for insulation or show
    • Primitive feathers have been brief, down-like filaments, on the again of the top, the arms, beck, again, and high and backside of the tail
    • Feathers have additionally been discovered on sides of the physique, in patches
    • Chen, Dong, and Zheng advised that primarily based on the patches and randomness of the patches, it was most likely coated in feathers when it was alive
    • There’s a niche between the feathers and bones, which have been most likely crammed in by pores and skin and muscle tissue
    • Scientists discovered by wanting by means of a microscope that the filaments have been darkish alongside the sides and light-weight inside, so they could have been hole like feathers of recent birds
    • Feathers are too dense to look at single constructions, however could have had two kinds of filaments, thick and skinny, the place the thick ones have been stiffer. The feathers could have had a central quill with thinner projections or barbs popping out, just like trendy chook feathers, however with extra primitive constructions
    • In 2018, Evan Saitta and others did a examine that discovered the thick filaments may very well be bundles of skinny filaments. They discovered the thick filaments didn’t have any calcium phosphate, which is present in trendy feather quills
    • Prompt that Sinosauropteryx feathers have been single-branch filaments, although perhaps typically they joined on the base into tufts, type of like down-like feathers
    • The filaments have been controversial at first, and thought by some to be collagen fibers as an alternative of primitive feathers, and that these fibers shaped a frill on the again and underneath the tail, like some trendy aquatic lizards. Not having feathers would imply Sinosauropteryx was not essentially the most basal identified theropod with feathers, and would additionally name into query the idea that feathers developed for insulation first, not flight, and that they appeared in basal dinosaurs that developed into birds
    • Many scientists didn’t agree that the constructions have been fibers
    • Then a 2017 paper by Smithwick and others discovered that the constructions have been undoubtedly not collagen fibers. They in contrast it to well-known collagen fibers within the ichthyosaur Stenopterygius, and so they discovered that the apparently shaft-like collagen fibers within the ichthyosaur have been truly scratch marks and cracks, and the shafts in Sinosauropteryx have been the precise fossilized constructions
    • Additionally they discovered no proof of the filaments having beaded constructions just like these present in decaying collagen in trendy sea mammals, and advised that elements of the fossil was preserved in 3D and forged shadows that regarded like beaded constructions in low high quality photographs
    • Within the holotype within the stomach there’s a pigmented space that was thought to presumably be traces of organs, perhaps the liver, that John Ruben and others described as a part of a crocodilian-like “hepatic piston” respiratory system, a specialised respiratory mechanism the place muscular tissues connected to the liver and pubic bones of the hip pull the liver again to inflate the lungs, for brief bursts of operating/exercise
    • A later examine discovered that the pigmented space was most likely a part of an organ or one thing contained in the physique, the organs would have been distorted and flattened by means of the fossilization course of
    • Darkish pigment was additionally discovered within the eye space
    • First dinosaur to have colours scientifically described
    • Had a reddish, gentle banded tail coloration
    • Nick Longrich advised in 2002 it had a banding sample on the tail, alternating between darkish and light-weight colours, as a result of the darkish banded areas have been so evenly spaced it couldn’t have been from random separation of fossil slabs, and they also have been fossilized pigments. Additionally Sinosauropteryx could have had countershading, with darkish feathers on the highest of the physique and lighter colours on the underside, and bands on tail to assist camouflage
    • Fucheng Zhang and others in 2010 supported the thought, once they discovered proof of preserved melanosomes, and so they confirmed the darkish and light-weight tail banding of Sinosauropteryx. They in contrast melanosome sorts to these in trendy birds and got here up with a variety of colours, and located the darker Sinosauropteryx feathers within the tail have been chestnut or reddish brown (melanosomes have been spherical in form). Don’t know the colour of the lighter stripes as a result of some pigments degrade and may’t inform from fossils. Discovering these melanosomes is extra proof these constructions have been feathers
    • Later findings discovered it had a bandit masks like a raccoon round its eyes and had countershading patterns on its physique, often related to an animal in an open habitat with not a lot overlaying, and never a dense forest, which suggests the Jehol Biota (Yixian Formation and Jiufotang Formation) had a wide range of habitat sorts
    • With the countershading, Sinosauropteryx may mix in
    • Dinosaurs had good imaginative and prescient, in order that they wanted camouflage. For Sinosauropteryx, wanted to mix in to keep away from predators and likewise to sneak up on prey
    • Bandit masks could have helped with protection, to be a warning sign, although Sinosauropteryx was so small it most likely wasn’t a menace to bigger theropods
    • As a result of the tail was so lengthy, it most likely couldn’t maintain it’s tail completely horizontal on a regular basis, so having the banded tail perhaps helped throw off predators and prey, by being a distracting and drawing consideration away from the top and physique. Or presumably the banding made the tail much less recognizable to predators
    • In all probability spent quite a lot of time within the solar, not in shade
    • Lived in an space with freshwater lake, gymnosperm forests (like conifers), and many bugs, bivalves, and gastropods, in addition to mammals and birds. A number of volcanic eruptions, wildfires, and noxious gases that got here from the lakes. However it was temperate with moist and dry seasons (yearly temperature was 50 F (10 C)

    Enjoyable Truth:
    The Carnian Pluvial Explosion was a really wet interval within the Triassic when many early dinosaurs present up within the fossil file.


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