Chirostenotes ‭(‬Narrow handed‭)

Short Info

Chirostenotes ‭(‬Narrow handed‭)

Phonetic : Ky-ore-sten-o-teez.

Named By : Charles Whitney Gilmore‭ ‬-‭ ‬1924

Diet : Possibly Omnivore

Size : Estimated 2 meters long

Type of Dinosaur : Small Theropod

Type Species : C.‭ ‬pergracilis‭ (‬type‭)‬,‭ ‬C.‭ ‬elegans

Found in : Canada‭ ‬-‭ ‬Alberta‭ ‬-‭ ‬Dinosaur Park Formation

When it Lived : Late Jurassic, 79-67 million years ago

Chirostenotes (/,kaIroUstI’noUti:z/ KY-ro-sti-NOH-teez; named from Greek ‘narrow-handed’) is a genus of oviraptorosaurian dinosaur from the late Cretaceous (about 76.5 million years ago) of Alberta, Canada. The most common species is Chirostenotes pergracilis.

Chirostenotes skeletalGregory Funston, CC BY 4.0, via Wikimedia Commons

Chirostenotes has a tangled history of discovery and the naming. Initial fossils for Chirostenotes comprised of a pair hands, were discovered in the hands of George Fryer Sternberg near Little Sandhill Creek in the Campanian Dinosaur Park Formation of Canada which produced the largest number of dinosaurs found in the entire Canadian formation. The specimens were examined by Lawrence Morris Lambe who, however, passed away before he could officially identify the fossils. The year 1924 saw Charles Whitney Gilmore adopted the name that he discovered in Lambe’s notes, and then identified and named the type of species Chirostenotes pergracilis. The name itself originates from the Greek”cheir “hand”, and stenotes “narrowness”. The precise name translates to “throughout”, per~, “gracile”, gracilis in Latin. The Holotype corresponds to NMC 2367, which is the hand pair. Another fossil related to Chirostenotes is the specimen CMN 776, a pair of jaws with bizarre teeth that were initially described to by Gilmore in the early days to Chirostenotes pergracilis. Since it has been established that Chirostenotes was an oviraptorosaur without teeth The jaws have been named Richardoestesia and come from an unknown dinosaur, possibly an dromaeosaurid.

Chirostenotes pergracilis handGregory Funston, CC BY 4.0, via Wikimedia Commons

Chirostenotes was not the only name that was assigned to. Feet were later discovered in CMN 8538, a specimen, then later in 1932 Charles Mortram Sternberg gave them the name Macrophalangia Canadensis which means “large toes from Canada’. Sternberg accurately identified the toes as part of an animal that ate meat, but believed they were an ornithomimid. In 1936, its jaws on the lower side the specimen CMN 876 were discovered in the hands of Raymond Sternberg near Steveville and in 1940, he named them Caenagnathus collinsi. The name is a generic term meaning’recent jaw’, derived from Greek Kainos, “new”, and gnathos, “jaw”; the specific name honors William Henry Collins. The jaws with no teeth were first thought to be that of birds.

The precise connection between the findings became apparent. In 1960, Alexander Wetmore concluded that Caenagnathus was not a bird , but an ornithomimid. In 1969, Edwin Colbert and Dale Russell claimed it was possible that Chirostenotes as well as Macrophalangia were the identical animal. In the year 1976 Halszka Osmolska described Caenagnathus as an Oviraptorosaurian. In 1981, the release of Elmisaurus which was an Asian form in that both feet and hand were preserved, demonstrated the validity in Colbert and Russell’s speculation.

The year 1988 was the time a piece of material of a storage facility from 1923 was found and examined with Philip J. Currie and Dale Russell. This fossil helped connect the other discoveries to form a single dinosaur. Because the initial name given to these remains was Chirostenotes it was the only name accepted as being valid.

Currie as well as Russell also addressed the more complicated question of a secondary form of the species that was present in the specimen. In 1933, William Arthur Parks had named Ornithomimus Elegans, based upon the specimen ROM 781, a different foot that was found in Alberta. in 1971 Joel Cracraft, still in the belief that Caenagnathus could be a bird had identified a different type that was a part of Caenagnathus: Caenagnathus sternbergi, basing it on the the specimen CMN 2690, which had a tiny lower jaw. In 1988, Russell and Currie believed that the fossils could be an edgier morph that of Chirostenotes pergracilis. In 1989 , however, Currie thought that they could be a different species and named it as a different species of the closely similar Elmisaurus: Elmisaurus elegans. In 1997, the species was changed to Chirostenotes elegans, by Hans-Dieter-Sues. The species was transferred into the new Genus Leptorhynchos in 2013.

A number of larger skeletons from earlier Maastrichtian Horseshoe Canyon Formation of Alberta and the later Maastrichtian Hell Creek Formation of Montana and South Dakota have been referred to Chirostenotes in the past, however newer studies have revealed that they belong to a number of new species. It is worth noting that the Horseshore Canyon formation specimen was changed to Epichirostenotes in 2011 and those from the Hell Creek Formation specimens have been assigned to the Genus Anzu.

In 2007, a cladistic analysis conducted by Philip Senter cast doubt on the notion that all the massive Dinosaur Park Formation fossils belonged to the same species. Coding the jaw and hand specimens separately proved that, although the Caenagnathus Holotype was in the lower position within the Caenagnathidae generally associated with it however, this Chirostenotes pergracilis holotype has been classified on the level of an advanced Oviraptorosaurian as well as an oviraptorid. The subsequent studies showed evidence that Caenagnathus jaws did join with other caenagnathids, however they were not Chirostenotes. New specimens identified by Funston and colleagues. (2015) as well as Funston & Currie (2020) revealed they believed that Chirostenotes can be distinguished as a species that is distinct from Caenagnathus.

Chirostenotes was identified by long arms that ended in short, straight claws that were slender, and legs that were long, powerful, and with slim toes. In the year 2016 Paul estimated its length as 2.5 meters (8.2 feet) and the weight was 100 kilograms (220 pounds) and the previous year, Molina Perez and Larramendi provided an approximate size that was 2.6 meters (8.5 feet) and 40 kilograms (88 tons).

Source: Wikipedia