Episode 478: Is Nanotyrannus again?

Episode 478: Is Nanotyrannus again? Nanotyrannus debate continues (was it its personal dinosaur or was it truly T. rex?), plus a brand new debate in regards to the evolution of one other ferocious tyrannosaur, Daspletosaurus, and a enjoyable reality a few child T. rex you’ve in all probability by no means heard of.


  • A brand new paper considers Nanotyrannus to be a legitimate genus (separate from Tyrannosaurus) supply
  • Daspletosaurus could not have advanced through anagenesis supply
  • The Kids’s Museum of Indianapolis has a brand new Allosaurus with pores and skin impressions, stomach ribs, and proof of accidents supply
  • Trinity the T. rex will probably be on show on the Aathal Dinosaur Museum in Zurich, Switzerland for many of 2024 supply
  • The Royal Mint has three new dinosaur cash supply


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The dinosaur of the day: Bistahieversor

  • Eutyrannosaurian theropod dinosaur that lived within the Late Cretaceous in what’s now New Mexico (Kirtland Formation and Fruitland Formation)
  • Regarded like different massive tyrannosaurs, with an enormous head with a deep cranium and sharp tooth, quick arms, and a protracted tail
  • High of the cranium of the holotype seems to be nearly like ornamentation you’d see on a ceratopsid frill
  • Had a deep snout, which helps present that it wasn’t simply Tyrannosaurus and different derived tyrannosaurs that had this function
  • Deep cranium good for bone crushing
  • Earlier than Bistahieversor, thought that solely later tyrannosaurs like Tyrannosaurus had deeper snouts
  • Doable that obstacles just like the newly forming Rocky Mountains and rising sea ranges remoted Bistahieversor from northern tyrannosaurs
  • Had some early options of tyrannosaurs too, within the snout, brow, and with projections over the eyes
  • In all probability had quick arms, based mostly on having a deep cranium for bone crushing (didn’t want lengthy arms to go after prey, much like Tyrannosaurus)
  • Had 64 tooth
  • Had extra tooth than Tyrannosaurus (had about 60)
  • Had an additional opening above its eye, and a keel alongside the decrease jaw
  • Further opening above the attention could have been for an air sac to assist maintain the cranium lighter
  • Additionally had a posh joint on the “brow” to assist stabilize the cranium
  • Comparable in dimension to Daspletosaurus
  • Adults estimated to be about 30 ft (9 m) lengthy and weigh at the least one ton
  • Gregory Paul estimated it to be 26 ft (8 m) lengthy and weigh 2.75 tons, and in 2016 Molina-Pérez and Larramendi estimated it to be 29.5 ft (9 m) lengthy and weigh 3.6 tons
  • Juvenile discovered is about half the size of the grownup
  • 2020 examine CT scanned and reconstructed the holotype and juvenile’s skulls
  • Holotype cranium was about 3.3 ft lengthy (over 1 m)
  • Capable of see the mind cavity, sinus cavities, pathways of some nerves and blood vessels, and extra
  • Discovered Bistahieversor had mind, ear, and sinus methods practically an identical to tyrannosaurids like Tyrannosaurus, Gorgosaurus, and Alioramus
  • Attention-grabbing as a result of it’s not a tyrannosaurid
  • Bistahieversor was one of many first tyrannosauroids to get actually huge (in between basal species and tyrannosaurids, so helps fill in gaps on how tyrannosaur brains advanced)
  • A lot of air-filled sinuses across the mind and ear
  • Helps present that the tyrannosaurid-style mind and sinus system had been already there earlier than the rise of the Tyrannosauridae
  • Bigger sinuses could have helped maintain the cranium lighter, helped with listening to at its bigger physique dimension, or helped enhance floor space to maintain cool
  • In all probability much like tyrannosaurids by way of intelligence and sensory skills
  • Discovered massive olfactory bulbs, so in all probability had a very good sense of odor
  • Additionally proof of being agile and conserving its gaze steady whereas shifting its head
  • May hear low frequency sounds effectively
  • Had binocular imaginative and prescient, so might see pretty effectively, although it did have small optic lobes (however that doesn’t essentially imply it had poor imaginative and prescient)
  • Sort and solely species is Bistahieversor sealeyi
  • Also called the “Bisti Beast”
  • 4 specimens discovered, together with a juvenile
  • First fossils of a partial cranium and skeleton had been described in 1990 and considered a specimen of Aublysodon (a carnivorous dinosaur solely identified from a tooth)
  • Extra fossils, together with a partial cranium and juvenile skeleton, had been described in 1992
  • Then in 1998, the “Bisti Beast” was discovered, and features a full cranium and partial skeleton
  • In 2000, Thomas Carr and Thomas Williamson instructed these 4 people had been Daspletosaurus as an alternative of Aublysodon
  • Then in 2010 Carr and Williamson redescribed the fossils and named them Bistahieversor sealeyi
  • Holotype was airlifted by a helicopter by the New Mexico Military Nationwide Guard (they volunteered as a part of a coaching train)
  • Took about two years to arrange the cranium
  • Holotype and juvenile had scars on the bones both from contaminated accidents or from accidents that had been therapeutic once they died
  • Juvenile cranium is badly broken
  • The identify, based on the paper that named it, comes from “Bistahi, place of the adobe formations (Navajo) in reference to the Bisti Wilderness Space; eversor, destroyer (Greek) in reference to the presumed predatory habits of the animal; Sealey, in reference to Mr. Paul Sealey, Analysis Affiliate on the NMMNH, in recognition of his discovery of the holotype specimen”
  • Sealey was a volunteer researcher who discovered the holotype fossils on a weekend journey in 1997
  • Different dinosaurs that lived across the similar time and place included the ankylosaurs Ahshislepelta and Ziapelta, the pachycephalosaur Stegoceras, the ceratopsids Terminocavus, Navajoceratops, and Pentaceratops, hadrosaurs together with Parasaurolophus, dromaeosaurs, and ornithomimids
  • Different animals that lived across the similar time and place included pterosaurs, turtles, alligatoroids, and fish

Enjoyable Truth:

There’s a potential juvenile T. rex specimen that would finish the Nanotyrannus debate, however it’s in a non-public assortment so it hasn’t been studied.

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