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Episode 376: A brand new velociraptor relative with hornlets


    Episode 376 is all about Tenontosaurus, the ornithopod which is generally identified for being eaten by Deinonychus.

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    On this episode, we talk about:


    • A brand new raptor, Kuru kulla, was present in Mongolia with small hornlets above its eyes supply
    • Lower than ten full, articulated, sauropod necks have been described supply
    • The Cleveland Museum of Pure Historical past is getting its personal Dippy the Diplodocus supply
    • A tracksite on a sheer cliff was recreated in VR so guests can see it supply
    • Dwayne “The Rock” Johnson revealed he’s a fan of Stan the T. rex, however purchased a duplicate cranium and never the unique skeleton supply

    The dinosaur of the day: Tenontosaurus

    • Ornithopod that lived within the Early Cretaceous in what’s now the U.S. (Montana, Wyoming, Oklahoma, Texas, Idaho, Utah, Maryland)
    • Regarded type of like Iguanodon, with a cumbersome physique, walked on two legs or all fours, however had an extended tail
    • Medium to massive dimension
    • Estimated to be 21 to 26 ft (6.5 to eight m) lengthy and weigh between 1 to 2 tonnes
    • Had a protracted, broad, stiff tail
    • Had a really lengthy tail about two thirds the size of its physique
    • Had a comparatively lengthy forelimb
    • Had a U-shaped beak
    • Herbivorous
    • Numerous vegetation round: ferns, cycads, and possibly some flowering vegetation
    • Most likely ate ferns and shrubs, possibly additionally wooden and fruit
    • Low browser; if on two legs, might have browsed meals at a most top of 10 ft (3 m) from the bottom
    • Two species: Tenontosaurus tilletti and Tenontosaurus dossi
    • Kind species is Tenontosaurus tilletti
    • Genus identify means “sinew lizard”
    • John Ostrom described Tenontosaurus tilletti in 1970
    • Winkler, Murry, and Jacobs described Tenontosaurus dossi in 1997
    • First specimen present in 1903 by a area celebration from the American Museum of Pure Historical past, a fragmentary partial skeleton in Massive Horn County, Montana
    • Extra expeditions by Barnum Brown in 1931, 1932, 1933, 1938, discovered “partial stays of a minimum of 18 people”
    • Barnum Brown informally named it “Tenantosaurus” to discuss with the stiff tendons in its again and tail
    • A area crew from the College of Oklahoma collected at two websites in 1940, “one producing a big, just about full grownup related to a minimum of 4 small juveniles”
    • Al Silberling, a personal collector, excavated two specimens for Princeton College in 1948 and 1949 (not been described, however Brown informally dubbed it Tenantosaurus)
    • John Ostrom led an expedition of Yale College from 1962 to 1966 of the Cloverly Formation in Montana and Wyoming, and located 40 extra specimens
    • Extra specimens have been discovered since 1970 from the Cloverly Formation, Antlers Formation in Oklahoma, Paluxy Formation in Texas, Wayan Formation in Idaho, Cedar Mountain Formation in Utah, and Arundel Formation in Maryland
    • Commonest dinosaur within the Cloverly Formation
    • “Greater than 80 specimens recovered from the Cloverly Formation since 1903 could be attributed to Tenontosaurus, one of the crucial plentiful Early Cretaceous dinosaurs in North America”
    • Antlers Formation of Oklahoma has 16 partial or almost full skeletons of T. tilletti
    • Features a almost full, articulated, subadult or presumably early grownup
    • Tenontosaurus dossi present in Parker County, Texas (Twin Mountains Formation)
    • In 1970 D Andrew Thomas studied the cranium of Tenontosaurus tilletti
    • CT scanned the cranium, which was discovered within the Antlers Formation of Oklahoma
    • That specimen, the center a part of the tail was first discovered (partially eroded from the slope of a hillside inside a drained pond)
    • Discovered a sclerotic ring, although it was poorly preserved
    • In 1990 Catherine Forster studied the skeleton of Tenontosaurus tilletti, discovered within the Cloverly Formation
    • Tenontosaurus dossi first present in Texas (two articulated skeletons), and is taken into account to be extra primitive than Tenontosaurus tilletti
    • Specimens discovered have been “unscavenged carcasses entombed in a brackish-water lagoonal or estuarine sands”
    • Fossils present in Oklahoma and Doss Ranch Website in Texas in addition to Wyoming and Montana
    • In what’s now Wyoming and Montana, the local weather modified drastically throughout Tenontosaurus’s time, from dry to tropical, which appeared to coincide with a rise within the variety of Tenontosaurus (so might have been an adaptable dinosaur)
    • In 2008, Andrew Lee and Sarah Werning studied the 8 yr previous Tenontosaurus
    • Medullary bone tissue discovered within the specimen (thigh and shin bone). Specimen was about 8 years previous and never absolutely grown, based mostly on histology
    • Medullary bone has a lot of calcium and types when feminine birds and dinosaurs lay eggs
    • Determining the age of reproductive maturity helps work out dinosaur physiology, lifespan, and reproductive methods
    • Analyzed three dinosaurs identified to be feminine, based mostly on them having medullary bone
    • Included Allosaurus that was 10 years previous, T. rex that was 18, and Tenontosaurus that was 8, based mostly on histology
    • Doable all of them reached sexual maturity a lot earlier
    • As a prey dinosaur, can be helpful to Tenontosaurus to breed early
    • In 2012 Sarah Werning wrote about ontogenetic osteohistology of Tenontosaurus tilletti
    • Numerous specimens, to indicate progress sequence
    • Discovered subadults typically had “double LAGS”, “two very closely-spaced LAGs that possible didn’t symbolize a complete yr of progress between them”
    • Discovered indicators of dramatically slowed progress in grownup Tenontosaurus, which occurred for a number of years earlier than it was executed rising/stopped rising
    • Early progress and into subadulthood, Tenontosaurus tilletti was a quick grower, till it turned reproductively mature. Then progress slowed down
    • Much like Rhabdodon and Zalmoxes however totally different from different iguanodontians, which grew rapidly till they have been absolutely grown
    • Could possibly be why Edmontosaurus and different related dinosaurs acquired a lot greater (they by no means slowed their progress till they have been executed rising)
    • However Tenontosaurus was sexually mature earlier than it was absolutely grown
    • Deinonychus fossils and tooth have been discovered related to Tenontosaurus tilletti (in over 50 Tenontosaurus websites, 14 even have Deinonychus fossils)
    • About 20% of Tenontosaurus fossils have been discovered near Deinonychus. Might imply Deinonychus was one of many major predators of Tenontosaurus
    • An grownup Deinonychus is smaller than an grownup Tenontosaurus, so unlikely to assault alone
    • Most Tenontosaurus specimens discovered with Deinonychus are about half-grown
    • Some scientists suppose this might imply Deinonychus was a pack hunter, however there’s probably not proof for coordinated looking (presumably they’d mobbing habits), and there’s proof Deinonychus was cannibalistic and went into feeding frenzies round Tenontosaurus
    • Deinonychus most likely most well-liked juvenile Tenontosaurus, although might have scavenged bigger Tenontosaurus or gone after sick or injured adults
    • Lined Deinonychus in episode 14
    • One Tenontosaurus discovered with chew marks from Deinonychus
    • In 1992 Desmond Maxwell and John Ostrom wrote concerning the taphonomy and implications of Tenontosaurus and Deinonychus being discovered collectively
    • Supported the thought of Deinonychus being a pack hunter, and that Tenontosaurus “was the precise meals desire of the Deinonychus predator inhabitants”
    • When Ostrom first described Tenontosaurus, he wrote that the Deinonychus specimens related to fragments of Tenontosaurus in a quarry is likely to be proof that “Deinonychus most likely hunted in packs of six, eight, or extra predators, a bunch able to carry down a lot bigger prey animals, comparable to Tenontosaurus. That view has usually been accepted ever since, however not with out query”
    • Discovery of Tenontosaurus stays preserved with shed Deinonychus tooth (discovered by MoR group)
    • “New discovery seems to substantiate Ostrom’s conclusion that the repeated affiliation of Deinonychus and Tenontosaurus stays signifies a transparent meals desire on the a part of Deinonychus”
    • In 2019, T. C. Hunt and others wrote about pathologies in Tenontosaurus tilletti
    • Specimen present in 2001, almost full, from the Antlers Formation in Oklahoma
    • Practically full specimen, not absolutely grown (nicknamed “The Good Tenontosaurus” as a result of it was so full)
    • This specimen was about 16.5 ft (5 m) lengthy
    • Used CT scans and analyzed the fossils and located 5 pathologies, 4 which got here from some kind of trauma
    • Appears it fell and broke ribs, broke a toe, and had a bony outgrowth on the hand bone
    • Accidents healed, however would have damage its capacity to get meals or escape predators
    • Prone to extra infections after
    • Had osteomyelitis in and across the ribs (irritation/an infection of the bone) and on the left toe bone
    • Additionally discovered a Brodie abscess, a gap within the left hand that shaped when micro organism that produced pus entered the bone
    • Doable the Brodie abscess occurred earlier than the opposite accidents, or developed after the autumn (unclear, because it’s not potential to evaluate the state of the mushy tissue)
    • Solely the second time a Brodie abscess was present in a dinosaur, and the primary time present in an herbivore
    • Would have had a lot of swelling, and been onerous to stroll, and would have been painful to make use of its left hand
    • Doable it lived a number of months after the accidents, based mostly on the best way it healed and its infections
    • Different animals that lived across the identical time and place embrace carchaodontosaurs like Acrocanthosaurus, nodosaurs, dromaeosaurs like Deinonychus, oviraptors, sauropods, crocodilians, turtles, fish, and mammals
    • Can see a statue of Tenontosaurus being attacked by Deinonychus on the Goseong Dinosaur Museum in South Korea

    Enjoyable Reality:
    Kuru & Shri are the primary velociraptorines named from the identical location, and so they have been each named inside the final yr.


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