I Know Dino Podcast Present Notes: Gorgosaurus (Episode 121)

The dinosaur of the day: Gorgosaurus

• Title means “fierce lizard”
• Tyrannosaurid that lived within the Cretaceous in western North America
• Fossils present in Alberta and presumably Montana
• One species: Gorgosaurus libratus (different species have been assigned, although they weren’t appropriate)
• Species identify means “balanced”
• Described in 1914 by Lawrence Lambe
• Holotype is an almost full skeleton and a cranium, discovered by Charles M. Sternberg in 1913 in Dinosaur Park Formation in Alberta, and was the primary tyrannosaurid discovered with an entire hand
• A minimum of 12 Gorgosaurus specimens have been discovered
• AMNH collected a whole bunch of dinosaur specimens round that point, and located 4 full Gorgosaurus skulls, three with skeletons. Matthew and Brown described them in 1923
• Matthew and Brown described a fifth skeleton (Charles Sternberg present in 1917 and bought to AMNH). It was smaller than different specimens, and just like different juvenile tyrannosaurids, with longer limb proportions and a decrease, lighter cranium, however they mentioned it was a brand new species, Gorgosaurus sternbergi (now thought-about to be a juvenile Gorgosaurus libratus)
• Most intently associated to Albertosaurus (additionally distantly associated to T-rex)
• A part of the subfamily Albertosaurinae (extra intently associated to Albertosaurus). Albertosaurinae had extra slender builds, had been smaller, had decrease skulls, and longer tibias
• Similar to Albertosaurus, however refined variations in tooth and cranium
• Some folks suppose Gorgosaurus libratus is Albertosaurus (Gorgosaurus could be a junior synonym, since Albertosaurus was named first)
• In 2003 a group discovered that Gorgosaurus was completely different from Albertosaurus (had barely longer legs, and cranium was just a little completely different. Gorgosaurus was largely present in older rocks than nearly all of Albertosaurus fossils, so some suppose Gorgosaurus was an ancestor to Albertosaurus)
• William Diller Matthew and Barnum Brown thought Gorgosaurus and Albertosaurus had been the identical in 1922, and Dale Russell formally reassigned Gorgosaurus to Albertosaurus libratus in 1970, however not everybody agrees (together with Phil Currie, who mentioned there are undescribed tyrannosaurids from Alaska, New Mexico and different components of North America that might assist reply the query). Gregory Paul mentioned Gorgosaurus could also be ancestral to Albertosaurus sarcophagus
• Some species had been incorrectly named Gorgosaurus, together with a small tyrannosaurid from Hell Creek (named by Charles Gilmore in 1946 as Gorgosaurus lancensis and since renamed Nanotyrannus by Bob Bakker in 1988, which some folks now suppose is only a juvenile T-rex). In 1955, Evgeny Maleev named Gorgosaurus lancinator and Gorgosaurus novojilovi from two tyrannosaurids present in Mongolia, however in 1992 Kenneth Carpenter renamed the one Maleevosaurus novojilovi, and now they’re each thought-about to be juvenile Tarbosaurus bataar
• In 1856, Joseph Leidy described two tyrannosaurid tooth (nothing else of the animal discovered) and known as them Deinodon. Matthew and Brown mentioned in 1922 they had been the identical as Gorgosaurus tooth, however since there have been no different fossils they didn’t synonimize them, and known as it Deinodon libratus (nevertheless, tyrannosaurid tooth usually look the identical, so not for positive it’s Gorgosaurus). Deinodon is often thought-about to be a nomen dubium now
• Some tyrannosaurids from Two Medication and Judith River in Montana are most likely Gorgosaurus (not clear if it’s Gorgosaurus libratus or a brand new species).
• One specimen, now on the Youngsters’s Museum in Indianapolis, has plenty of pathologies (healed leg, rib fractures, an infection that led to everlasting tooth loss, and presumably a mind tumor)
• Holotype had some pathologies, together with healed fractures and a deformed toe, attainable from a battle with one other dinosaur
• One other Gorgosaurus had many pathologies (fractures, a number of ribs healed from fractures, lesions from a chunk on the face), proof that it was therapeutic earlier than it died
• One other Gorgosaurus had chunk marks on its face, in addition to a “mushroom-like hyperostosis of a proper pedal phalanx” which may be just like a pathology discovered on an unidentified ornithomimid
• Gorgosaurus was an apex predator that consumed ceratopsids and hadrosaurs
• Co-existed with Daspletosaurus (comparable in measurement, however presumably there was some area of interest differentiation)
• Uncommon for 2 tyrannosaur genera to co-exist. Some thought Gorgosaurus hunted the hadrosaurs and Daspletosaurus went for the ceratopsids, however one Daspletosaurus was discovered with a hadrosaur in its intestine, and a Daspletosaurus bonebed had three Daspletosaurus with 5 hadrosaurs (no proof of Gorgosaurus pack conduct)
• Gorgosaurus seems to be extra frequent within the north and Daspletosaurus within the south
• Cranium was just a little smaller than Daspletosaurus (39 in or 99 cm lengthy), however massive for its physique (had massive fenestrae to scale back weight)
• Grew as much as 26-30 ft (8-9 m) lengthy and weighed about 2.5 tons
• Gorgosaurus was a juvenile for about half its life, after which had fast progress spurts. Since no intermediate measurement predators have actually been discovered, the juveniles most likely stuffed a distinct segment (just like Komodo dragons)
• Smaller Gorgosaurus that had been discovered had longer tibias than femurs, so had been quick operating
• As a juvenile, Gorgosaurus most likely went after ornithomimids (sooner prey)
• Grownup Gorgosaurus had lengthy hindlimbs (largest Gorgosaurus femur was 41 in or 105 cm lengthy)
• Had two-fingered forelimbs (forelimbs had been small, proportionately)
• Had two digits on every forelimb, and 4 digits on every hindlimb (first digit didn’t contact the bottom)
• Had a blunt snout, and nasal bones had been fused
• Had a round eye socket
• Had crests in entrance of eyes, like Albertosaurus and Daspletosaurus
• Had 26-30 maxillary tooth and 30-34 tooth within the decrease jaw
• Had a heavy tail
• Phil Currie discovered pores and skin impressions in 2001, and it was easy (like secondarily flightless birds pores and skin) and didn’t have scales (although scales had been discovered on the specimen, however had been extensively dispersed and small, and different patches of pores and skin had denser, bigger scales). This helps present that larger dinosaurs didn’t have feathers, since bigger animals naturally misplaced much less warmth as a result of smaller floor space to physique quantity ratio
• Tyrannosauridae (means “tyrant lizards”) are theropods
• Lived late Cretaceous, Asia and North America
• Often the most important predators
• Not many full specimens discovered for identified tyrannosaurids
• However many genera have full skulls
• Some tyrannosaurids had crests above eyes
• Small arms however lengthy legs
• Juvenile tyrannosaurids had longer legs, extra suited to operating quick, however that modified as adults

Enjoyable reality: 

Birds don’t solely use feathers for flight, show, camouflage, bodily safety, sensory inputs, water proofing, and insulation within the chilly, but in addition for staying cool within the solar. A examine again in 2004 in contrast kangaroos and emus in harsh solar within the Australian Outback and located that kangaroos may dissipate 75–85% of photo voltaic radiation with their fur however Emus may dissipate almost 100% of photo voltaic radiation with their feathers even if have darker colours. This permits emus to remain within the solar whereas Kangaroos keep within the shade in the summertime.

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