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Episode 367: One other ankylosaur with battle wounds


    Episode 367 is all about Anchisaurus, a sauropodomorph whose bones have been first considered human stays once they have been present in 1818.

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    On this episode, we talk about:


    • We talk about the Dinosaur Systematics & Colbert Prize periods from the Society of Vertebrate Paleontology annual assembly supply
    • A brand new hadrosauriform, Brighstoneus, has been described from the Isle of Wight, UK supply
    • The Mary Anning Rocks marketing campaign has submitted a planning utility for a statue of Mary Anning and her canine supply
    • The Perot Museum of Nature and Science in Dallas, TX has a reconstructed Alamosaurus supply
    • The Royal Ontario Museum in Toronto, Canada has a brand new gallery of Earth historical past together with dinosaurs supply

    The dinosaur of the day: Anchisaurus

    • Basal sauropodomorph that lived within the Early Jurassic in what’s now Connecticut and Massachusetts, US (Portland Formation)
    • Till lately thought-about to be a prosauropod
    • Regarded like a typical sauropodomorph, walked on two legs and had an extended neck and tail
    • Bipedal however might go on all fours
    • Estimated to be 6.6 ft (2 m) lengthy and weighed round 60 lb (27 kg)
    • Marsh’s Anchisaurus main (Ammosaurus, now thought-about to be Anchisaurus polyzelus) was between 8 to 13 ft ( 2.5 to 4 m) lengthy and weighed as much as 70 lb (32 kg)
    • Gregory Paul estimated Anchisaurus to be 7.2 ft (2.2 m) lengthy and weigh 44 lb (20 kg)
    • Lived in an arid setting, with moist and dry seasons
    • Had blunt tooth, in all probability ate vegetation
    • But additionally had a big thumb claw, presumably for protection, or grabbing tree branches
    • Might have been an omnivore
    • Regarded as a carnivore due to the claws. In response to Richard Swan Lull within the Fifties, thought Anchisaurus was “an alert, lively dinosaur preying upon the smaller vertebrates of his era, because the highly effective claws and well-developed tooth indicate”
    • Had palms that have been proportionally brief to its arms
    • Fossils discovered very early, so has an extended historical past
    • In 1973, Peter Galton wrote in regards to the prosauropods of North America (and the historical past of Anchisaurus)
    • Fossils first present in 1818 “throughout blasting operations for a nicely in East Windsor, Connecticut”
    • Regarded as human bones in 1820, then in 1821, tail bones have been reported, and Porter stated they weren’t human
    • Wyman in 1855 stated it was reptilian and Lull in 1912 referred the fossils to Anchisaurus colurus (will get to that title later)
    • First fossils discovered within the Connecticut Valley have been fragmentary and poorly preserved and now thought be indeterminate, although a few of its options recommend it’s not the identical species as those from Manchester (present in 1884)
    • In 1855 Edward Hitchcock, an ichnologist, reported fossils present in Springfield, Massachusetts, discovered throughout “blasting operations on the water retailers of the US Armory”
    • Wyman described the fossils in 1858 however didn’t title it
    • Fossils now at Amherst Faculty Museum of Pure Historical past
    • Broken from the blast, and a few bones might have been unintentionally thrown away by workmen or some individuals took them house, so fossils are incomplete
    • In 1863, Hitchcock’s son, Edward Hitchcock Jr. described the fossils in a complement to his father’s work on fossil footprints
    • Hitchcock Jr. contacted Richard Owen, who informed him to call a brand new genus based mostly on the fossils. Owen prompt Megadactylus, which suggests “giant finger” as a result of it had a big thumb
    • Hitchcock Jr. gave it the species title polyzelus, which suggests “a lot searched for” in Greek. Refers to his father making an attempt to determine for years what animal made the tracks in his work
    • In 1889, Marsh described a part of a skeleton discovered close to Springfield, Massachusetts, that Hitchcock described in 1865 as Megadactylus
    • Wrote, “It’s a typical member of the order Theropoda, and has apparently for its nearest allies within the outdated world, Thecodontosaurus, from the Trias of England, and Massospondylus, from the identical formation in South Africa”
    • Cope described the specimen extra in 1870 and Marsh renamed it to Amphisaurus (means “close to saurian”) in 1882, then once more to Anchisaurus (means “close to lizard”) in 1885 (each names have been “preoccupied”)
    • Extra fossils have been present in 1884 close to Manchester, Connecticut
    • In 1884, whereas bridges have been being constructed, beginner paleontologist Charles Owen noticed a block with a part of a skeleton in it. He informed Marsh, who acquired the block from Charles Wolcott, who owned the quarry. The block had the again half of the specimen
    • Marsh tried to get the entrance half, however the block with the entrance half was already a part of a bridge
    • Marsh named it Anchisaurus main in 1889 (“the bigger one”)
    • In 1969 the bridge was demolished and John Ostrom bought the block with the entrance half of the skeleton (in all probability the identical one? exhausting to know). He’d been searching for the block for 2 years, and realized bridge builders had purchased the block and used it in an area venture. So he surveyed greater than 60 bridges and discovered the place the fossils have been. Then when the bridge was scheduled to be demolished, he bought permission for his staff to look at it beforehand
    • Three well-preserved skeletons discovered close to Manchester, Connecticut, in addition to two fragmentary specimens
    • Marsh described the skeletons in a number of papers and based mostly on them named Ammosaurus (“sand saurian”) in 1891, Anchisaurus colurus (“the mangled one”) in 1891, and Anchisaurus solus in 1892
    • Anchisaurus solus is sort of full
    • In considered one of his papers, Marsh wrote, “probably the most slender and delicate dinosaurs but found, being solely surpassed on this respect by a few of the smaller bird-like types of the Jurassic”
    • Additionally renamed Anchisaurus main as Ammosaurus in 1891
    • The specimens from Manchester are actually considered the identical as Anchisaurus polyzelus
    • They’re housed on the Peabody Museum of Pure Historical past
    • In 1906 Friedrich von Huene stated Anchisaurus polyzelus resembled Anchisaurus colurus (each had elongate dorsal vertebrae) however nonetheless thought them to have sufficient variations to be completely different species
    • Huene additionally referred Anchisaurus polyzelus to Thecodontosaurus based mostly on comparable radius, tibia, and fibula (Thecodontosaurus polyzelus)
    • Lull in 1915 disagreed. Additionally stated that if Huene have been right, all Anchisaurus can be a synonym for Thecodontosaurus, since Anchisaurus polyzelus is the sort species
    • In 1932, Huene corrected this by referring Anchisaurus solus to Ammosaurus and made Anchisaurus colurus the sort species of Yaleosaurus
    • He referred Anchisaurus solus to Ammosaurus due to the similarities within the ilium, tibia, and dorsal vertebrae
    • In 1953 Lull accepted Yaleosaurus as legitimate however nonetheless acknowledged Anchisaurus polyzelus and Anchisaurus solus
    • Holotype of Anchisaurus polyzelus doesn’t embody cranium materials
    • In 1976 Peter Galton renamed Gryposaurus capensis bones present in South Africa (named in 1911) as Anchisaurus capensis
    • However now it’s considered a juvenile Massospondylus carinatus
    • Galton additionally acknowledged Anchisaurus polyzelus (present in Charles Wolcott’s quarry in Connecticut) and Ammosaurus main (present in Portland Beds)
    • Galton referred Anchisaurus solus to Ammosaurus main
    • Additionally discovered Anchisaurus colurus to be a junior synonym of Anchisaurus polyzelus and Yaleosaurus to be a synonym for Anchisaurus
    • In 2008, Gauthier and Gall discovered Ammosaurus main to be a junior synonym of Anchisaurus polyzelus
    • In 2010, Adam Yates wrote “A revision of the problematic sauropodomorph dinosaurs from Manchester, Connecticut and the standing of Anchisaurus Marsh”
    • Discovered that Anchisaurus polyzelus is the one legitimate one (different paleontologists had agreed, earlier)
    • Discovered all of the Wolcott Quarry specimens to be the identical species
    • Additionally discovered they may all be referred to Anchisaurus polyzelus
    • Wolcott quarry was since been stuffed in
    • Wolcott quarry specimens now on the Peabody Museum
    • In 2007 Sereno stated Anchisaurus was a nomen dubium, however Yates didn’t agree (not sufficient diagnostic characters “past these of basal Sauropodomorpha” discovered within the fragmentary holotype)
    • Yates stated Anchisaurus had seven distinguishing characters regarding the cranium, vertebral column, and pelvis, together with a slender sacral rib, and strange proportions of the posterior dorsal centra
    • Yates additionally supported Anchisaurus being a basal sauropodomorph
    • To recap, the sort species is Anchisaurus polyzelus
    • Genus title means “close to lizard”
    • Anchisaurus was a substitute title for Amphisaurus, which was a substitute title for Megadactylus (already the names for different animals)
    • Ammosaurus, Anchisaurus solus, Anchisaurus colurus (also referred to as Yaleosaurus) are actually thought-about to be synonyms of Anchisaurus polyzelus
    • All three dinosaur skeletons have been from the identical Early Jurassic-age Wolcott Quarry in Connecticut, however Marsh named all of them completely different species: Anchisaurus main (1889), Anchisaurus colurus (1891) and Anchisaurus solus (1892)
    • Laborious to inform that Anchisaurus polyzelus and the Wolcott Quarry skeletons have been the identical dinosaur as a result of they didn’t have too many overlapping elements of the skeleton to match. However Yates discovered similarities within the hip blade and a part of the fused vertebrae, which confirmed they have been all associated
    • Anchisaurus was named first, so the title sticks
    • In 2015, the sort specimen of Anchisaurus colurus turned the neotype of Anchisaurus and formally turned the species Anchisaurus polyzelus
    • Tracks that appear to match with Anchisaurus’s toes have been present in Nova Scotia, however exhausting to know for certain

    Enjoyable Reality:
    The Chicxulub crater that worn out the dinosaurs created sinkholes (cenotes) that supplied freshwater to the traditional Mayans.


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