żyrafy-i-kopytne: Tyrannosauridae

Evidence: 80 • authority: 72

Tyrannosaurus () is a genus of large theropod dinosaur. The type species Tyrannosaurus rex (rex meaning 'king' in Latin), often shortened to T. rex or colloquially T-Rex, is one of the best represented theropods. It lived throughout what is now western North America, on what was then an island continent known as Laramidia. Tyrannosaurus had a much wider range than other tyrannosaurids. Fossils are found in geological formations which have been dated to the late Maastrichtian age of the late Cretaceous period, 69 to 66 million years ago, with isolated specimens possibly indicating an earlier origin in the middle Campanian age. It was one of the last known members of the tyrannosaurids and am…

Evidence: 94 • authority: 72

Evidence: 48 • authority: 72

Giganotosaurus ( GIG-ə-NOH-tə-SOR-əs) is a genus of large theropod dinosaur that lived in what is now Argentina, during the Albian age of the Early Cretaceous period, approximately 111 to 106 million years ago. The holotype specimen was discovered in the Candeleros Formation of Patagonia in 1993 and is almost 70% complete. The animal was named Giganotosaurus carolinii in 1995; the genus name translates to "giant southern lizard", and the specific name honors the discoverer, Ruben Carolini. A dentary bone, a tooth, and some tracks, discovered before the holotype, were later assigned to this animal. The genus attracted much interest and became part of a scientific debate about the maximum siz…

Evidence: 43 • authority: 92

Estimation of maximum body size in fossil species: A case study using <i>Tyrannosaurus rex</i>.. Among extant species, the ability to sample the extremes of body size-one of the most useful predictors of an individual's ecology-is highly unlikely. This improbability is further exaggerated when sampling the already incomplete fossil record. We quantify the likelihood of sampling the uppermost limits of body size in the fossil record using Tyrannosaurus rex Osborn, 1905 as a model, selected for its comparatively well-understood life history parameters. We computationally generate a population of 140 million T. rex (based on prior estimates), modelling variation about the growth cu…

Evidence: 30 • authority: 92

T. rex cognition was T. rex-like-A critical outlook on diverging views of the neurocognitive evolution in dinosaurs.. A recent debate has emerged between Caspar et al. (2024) and Herculano-Houzel (2023) on inferring extinct dinosaur cognition by estimating brain neuron counts. While thought-provoking, the discussion largely overlooks the function of cognition, as well as partly neglects the difficulties involved in estimating neuron numbers, which according to us leads to oversimplified conclusions. We use this exchange as a springboard to further explore how extinct cognition might be studied and the potential pitfalls involved. One of the main emphases is on introducing basic concepts and…

Evidence: 30 • authority: 92

Prolonged growth and extended subadult development in the <i>Tyrannosaurus rex</i> species complex revealed by expanded histological sampling and statistical modeling.. Background Tyrannosaurus rex , one of the most iconic non-avialan dinosaurs, remains a central focus of paleobiological research. Growth modeling suggests T. rex exceeded 8,000 kg within two decades and had a lifespan approaching 30 years. However, this understanding of T. rex growth dynamics is dependent on single-point histological sampling of multiple skeletal elements and lacks specimens encompassing the earliest growth states. Methods We present the most comprehensive histological analysis of Tyrannosaurus o…

Evidence: 30 • authority: 92

A large tyrannosaurid from the Late Cretaceous (Campanian) of North America.. The Tyrannosauridae emerged as the dominant large predators in Laurasia during the Late Cretaceous. Their evolution in North America culminated with the replacement of Albertosaurinae, Daspletosaurinae, and Teratophonei, with masses of 2-3 tonnes, by the giant Tyrannosaurus in the late Maastrichtian, with a mass approaching or exceeding 10 tonnes. The origin of Tyrannosaurus remains enigmatic, but fossils suggest an origin in the Campanian-Maastrichtian of southern Laramidia. Here we describe an unusually large and robust tyrannosaurid tibia from the late Campanian aged Hunter Wash Member of the Kirtland Formation…

Evidence: 24 • authority: 72

The largest extant animal, as well as the largest animal to ever exist, is the blue whale. The maximum recorded weight was 190 tonnes for a specimen measuring 27.6 metres (91 ft), whereas longer ones, up to 33.6 metres (110 ft), have been recorded but not weighed. It is estimated that this individual could have a mass of 250 tonnes or more. The longest non-colonial animal is the lion's mane jellyfish (120 ft, 36.6 m). While controversial, estimates for the weight of the sauropod Bruhathkayosaurus suggest it was around 110–170 tons, with the highest estimate being 240 tons, if scaled with Patagotitan, although actual fossil remains no longer exist, and that estimation is based on described d…

Evidence: 24 • authority: 72

Scotty is the nickname for the Tyrannosaurus rex fossil, catalogued as RSM P2523.8, that was discovered in Saskatchewan, Canada in 1991. The fossilised remains were painstakingly removed, almost completely by hand, over two decades from the rock in which they were embedded. When the preparation was complete in 2011, an around 65% complete T. rex skeleton was revealed. Since its discovery and extensive subsequent study, Scotty has been referred to as the largest T. rex ever discovered in the world, the largest of any dinosaur discovered in Canada, and as one of the oldest and most complete fossils of its kind at more than 70% bulk. Scotty resides at the Royal Saskatchewan Museum's T. rex Dis…

Evidence: 24 • authority: 92

Behavioral implications of an embedded tyrannosaurid tooth and associated tooth marks on an articulated skull of <i>Edmontosaurus</i> from the Hell Creek Formation, Montana.. Because teeth can be taxonomically distinct, particularly for non-mammalian carnivores such as non-avian dinosaurs, teeth that have broken off in the bone of another animal during feeding, predation or antagonism can provide direct information on carnivore behaviour. Here, we report on a semi-complete, articulated adult Edmontosaurus skull (MOR 1627) from the Hell Creek Formation with an embedded theropod tooth in the nasal. To ascertain taxonomic identity of the preserved tooth tip, we compare standardized…