Episode 424: What the Titanic has to do with dinosaurs


Episode 424: What the Titanic has to do with dinosaurs. Plus two new dinosaurs, a sauropod and a hadrosaur that each present sudden variety of their locales; Ornithopods had larger brains than we thought; and extra

Information:

  • There’s a brand new macronarian sauropod, Yuzhoulong, that exhibits extra variety in Sichuan, China than beforehand thought supply
  • A brand new basal hadrosaurid, Malefica, named “witch” or “sorceress” was present in Huge Bend Nationwide Park supply
  • Ornithopods, and particularly hadrosaurs, had larger brains than we thought supply
  • Washington state remains to be engaged on getting a state dinosaur supply
  • South Australian Museum in Adelaide, Australia, has a brand new exhibit, Six Extinctions supply

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The dinosaur of the day: Silesaurus

  • Silesaurid dinosauriform that lived within the Late Triassic, in what’s now Poland (Keuper Claystone)
  • Seemed pretty dinosaur-like, with a protracted tail, and lengthy neck, and walked on all fours, and had an elongated cranium
  • Estimated to be about 7.5 ft (2.3 m) lengthy
  • Concerning the dimension of a giant canine
  • Flippantly constructed, and possibly was quick and energetic
  • Had a slender snout, with nostrils that pointed ahead
  • Had giant orbits within the cranium so in all probability had good imaginative and prescient
  • Had seven vertebrae within the neck
  • Had a slender pelvis
  • Had slender ribs (“strongly crushed, which made their preparation troublesome”)
  • Had lengthy, slender legs
  • Had gracile entrance limbs
  • In 2020, Piechowski and others regarded on the posture and the way the muscle groups of Silesaurus labored and located the forelimbs had been absolutely straightened and had smaller muscle groups for extending the limbs, retracting, and bending (as seen in early sauropods)
  • From the 2020 paper: “had pillar-erected hindlimbs like some pseudosuchians” and had “absolutely erect” forelimbs like early sauropods
  • Had a really slender humerus and “barely curved bone”
  • Had “restricted forelimb pronation”
  • Authors wrote: “The forelimb could make solely brief steps, prohibiting quick locomotion”
  • Discovered the “hindlimb appears to have been able to larger pace”
  • Had some diversifications to assist enhance pace and adaptability with the forelimbs
  • Had a “pillar-erect hindlimb posture just like that of some pseudosuchians” (earlier than, the group of ornithodirans had been thought to “have solely buttress-erect limb posture”
  • Had posture just like early sauropods
  • However Silesaurus additionally had a shorter humerus and extra elongated antebrachium, so “may make longer steps and achieve larger pace than early sauropods”
  • Silesaurus additionally had a sexy beak on the decrease jaw
  • Had a “comparatively low tooth rely”
  • Had small, conical, serrated enamel
  • Dzik, who named Silesaurus, wrote the enamel have “somewhat low conical form and worn suggestions” and weak serration
  • Not many enamel, like different early herbivorous dinosaurs
  • Dzik wrote “Within the form of their crowns and sample of serration, the enamel of Silesaurus usually are not just like these of carnivorous dinosaurs” (in all probability herbivory)
  • At first regarded as herbivorous however coprolites discovered later confirmed Silesaurus could have eaten bugs, such because the beetle Triamyxa
  • Could have used its beak to peck on bugs
  • In 2019 Martin Qvarnström and others revealed a research on the beetle-bearing coprolites
  • Comparatively giant dimension of the coprolites exhibits it was not from a small animal
  • Coprolites ranged from 1.2 to 2.1 in (31 to 54.5 mm) lengthy
  • Coprolites had a “skinny, clean outer coating and are gray to brown in color”
  • Abundance of beetles and smaller invertebrates within the coprolites present that “the coprolite producer intentionally focused beetles and comparable small terrestrial invertebrates as prey”
  • Discovered the “greatest candidate from the physique fossil file of the locality is the dinosauriform Silesaurus”
  • Anatomy of Silesaurus is just like “bird-like neotheropod dinosaurs and trendy birds”
  • Hypothesized that Silesaurus used its beak “to effectively peck small bugs off the bottom, a feeding habits analogous to some extant birds”
  • Discovered that the coprolites had been made by “a medium-sized animal that focused bugs as prey”
  • Additionally stated it was probably that this animal additionally regurgitated pellets, like trendy birds
  • Presumably regurgitated comfortable prey and plant fragments
  • Silesaurus had some characters just like birds, with a shorter, extra compact cranium; keratinous beak
  • To sum up: coprolites had been discovered close to Silesaurus fossils, and the dimensions and form of the coprolites, together with the beakiness of Silesaurus made it appear the coprolites got here from Silesaurus
  • Kind species is Silesaurus opolensis
  • Named by Jerzy Dzik in 2003
  • Fossils present in Silesia, Poland
  • Genus title means “Silesia lizard”
  • Discovered close to the town of Opole, therefore the species title
  • Present in clay pit in Krasiejow close to Opole, southern Poland
  • Discovered a number of hundred well-preserved bones
  • The paper describing Silesaurus stated there was “an accumulation of skeletons”
  • Had sufficient specimens so there was a “just about full restoration of the skeleton”
  • Collected greater than 400 bones, together with 4 partially articulated skeletons
  • The place the fossils had been discovered had quite a lot of uncovered claystone and mudstone that was comfortable and simply disintegrated in water, which made the fossils “susceptible to destruction by weathering”
  • Kind specimen is an incomplete skeleton
  • Cranium identified from disarticulated bones
  • Contains the jaw bones
  • In 2014, Piechowski and others proposed sexual dimorphism for Silesaurus
  • Analyzed hip bones of 20 Silesaurus specimens, and located variations within the muscle tendons, and interpreted that mature females had statistically bigger ossified tendons than proposed males
  • Unique paper stated Silesaurus was a dinosauriform, with the household unsure
  • Thought-about to be a dinosauriform (a bigger group that features dinosaurs), and till not too long ago, not a dinosaur (missing options equivalent to an enlarged deltopectoral crest, the muscle attachment on the higher arm)
  • However, did have some dinosaur traits, equivalent to a brevis shelf, a bone floor on the pelvis that was the place tail muscle groups may connect)
  • Hip bones had been organized like a saurischian
  • Although it had beak, didn’t have the predentary bone seen in ornithischians
  • Had leaf-shaped enamel, additionally seen in early ornithischians
  • Had similarities to ornithischians, like Lesothosaurus
  • From Dzik: “Crompton and Attridge (1986) and Sereno (1997) proposed that prosauropods may additionally have had a slender sexy beak on the anterior finish of the higher and decrease jaws. He referred to a raised bony platform on the premaxillae in Riojasaurus from the Los Colorados Formation of Argentina, and in Plateosaurus from the Knollenmergel of Germany. That is hardly seen within the authentic illustrations, which implies that these buildings usually are not simple to discern. This isn’t the case with Silesaurus, during which the realm for the beak is outstanding, however restricted to the decrease jaw”
  • “These similarities to herbivorous dinosaurs could imply that 1) Silesaurus is an early member of the ornithischian lineage, 2) belongs to the lineage resulting in each the Ornithischia and Prosauropoda after its emergence from the ancestral carnivorous inventory however previous to splitting, or 3) kind a lineage that developed herbivory independently of dinosaurs. The fossil file of the early Late Triassic evolution of dinosaurs is simply too incomplete to make an inexpensive alternative”
  • From the unique paper: “Silesaurus appears to be near the purpose of origin of dinosaurs each in respect to its construction and geological age”
  • Additionally from the unique paper: ““It exhibits many of the characters listed by Novas as diagnostic apomorphies for members of the lineage resulting in dinosaurs”
  • And from the unique paper: “A lot much less apparent is the connection of Silesaurus to dinosaurs as its skeletal anatomy is a somewhat weird mixture of primitive and superior characters”
  • Not sufficient of the cranium and arms discovered, which makes it onerous to find out
  • As of 2022, appears silesaurs now thought of to be dinosaurs
  • In episode 415, we lined the newest on Ornithoscelida, the proposal from 2017 that ornithischians developed from theropods and the mixture needs to be known as “Ornithoscelida”
  • The authors Norman and Baron and others now suppose ornithischians developed from silesaurs, after analyzing early dinosaurs and together with silesaurs
  • Different papers prior to now have additionally proposed silesaurs are ornithischians, such because the paper that described the silesaurid Sacisaurus
  • Silesauridae was named as a gaggle in 2010 by Langer and others, and there are a couple of dozen silesaurs
  • Nonetheless some debate over what’s included, equivalent to Pisanosaurus (lined in episode 354)
  • Silesaurus lived in a subtropical surroundings just like the Mediterranean right now, with monsoons in the summertime and dry winters
  • Different animals that lived across the similar time and place embody fish, phytosaurs, and early pterosaurs

Enjoyable Reality:

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