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a meat-eating coelurosaurian theropod dinosaur from the Late Cretaceous of North America.
Pronunciation: ri-KARD-o-es-TEE-zee-uh
Meaning: for Richard Estes
Author/s: Currie, Rigby, Sloan (1990)
Synonyms: Ricardoestesia
First Discovery: Alberta, Canada
Chart Position: 282

Richardoestesia gilmorei

Not so much a recognizable dinosaur as a set of long slender jaws with mysterious teeth, Richardoestesia, as it became known via a little Dino-George muddle involving a first revision, some stealth back-tracking, a load of handbag-throwing on internet mailing lists, and a sneaky second attempt at a first revision, was originally assigned to Chirostenotes. But that all changed when paleontologists realised that Chirostenotes was actually a toothless oviraptorosaur and the remains belonged elsewhere.

Named in honor of Richard Estes for his cracking research into small vertebrates of the Late Cretaceous, Richardoestesia is almost a complete mystery, but this hasn't curbed paleontologist's enthusiasm. Its small teeth are very distinct, sporting 5-6 denticles (serrations, or tiny "teeth" along the edge of the teeth, if you will) per millimetre, which some experts have interpreted as evidence of a fish-based diet. However, a strong groove along the side of the holotype jaw suggests it belongs to either a troodontid or a dromaeosaurid which are both carnivorous. Although known from a plethora of fossils not one of them is any use in reconstructing the body of Richardoestesia to help deduce its hunting strategy, because none of them are attached to a diagnostic bone, or any bone for that matter; they're all loose teeth.

Richardoestesia-like teeth have been reported from the Horseshoe Canyon and Scollard Formation's (both Maastrictian) of Canada, the Hell Creek, Lance (both Maastrictian) and Cedar Mountain (Barremian) Formation's of the USA, and other far-flung places. The first ever instance of a theropod tooth from the southern Pyrenees, found at L'Abeller in the Aren Sanstone Formation (Late Campanian) near Tremp, Spain, was described as "reminiscent of those belonging to Richardoestesia gilmorei" too. But given the enormous range in both time and place the chances that all of these remains actually belong to a single genus are slim.
(for Richard Estes and C.W. Gilmore)Etymology
One of the few dinosaurs to combine a paleontologist's christian and surname all-in-one, Richardoestesia is named in honor Richard Estes. Two spellings, Richardoestesia and Ricardoestesia (with and without the "h"), were used in the same paper in 1990, but George Olshevsky became first reviser when he used the former name in 1992, blissfully unaware that the authors actually preferred the latter. Hoping that no-one had spotted his earlier error, Olshevsky attempted to sneak out a second attempt at a first revision, but paleontologists were having none of it, so Richardoestesia it is, and no amount of foot-stamping is gonna change it. The species epithet, gilmorei, honors a second paleontologist—Charles Whitney Gilmore—who originally assigned these remains to Chirostenotes pergracilis.
The remains of what would become Richardoestesia were discovered at "Little Sandhill Creek" (Judith River Group) in Dinosaur Provincial Park, Alberta, Canada, by Charles Hazelius Sternberg and sons in 1917.
The holotype (NMC 343) is a pair of lower jaw bones. Isolated teeth from pretty much every Rocky Mountain state and province have also been assigned here.
Era: Mesozoic
Epoch: Late Cretaceous
Stage: Campanian
Age range: 84-71 mya
Est. max. length: ?
Est. max. hip height: ?
Est. max. weight: ?
Diet: Carnivore
Family Tree:
Richardoestesia isosceles
In 2001, Julia Sankey named Richardoestesia isosceles based on a single holotype tooth (LSUMGS 489:6238) from the Aguja (Campanian) Formation in Texas and a hatful of other teeth from eight different Formations across the USA and Canada. Although sporting similar denticles, the teeth are longer, straighter, and more triangular in shape than those of Richardoestesia gilmorei, hence the name. Some paleontologists reckon the teeth of Richardoestesia isosceles belong to a crocodile ancestor.
Richardoestesia asiatica
In 1995 Lev Nesov coined Asiamericana asiatica based on three unusually straight teeth (CCMGE 460/12457) from the Bissekty (Turonian-Coniacian) Formation of Uzbekistan, but couldn't decide if they belonged to a spinosaurid dinosaur or a fish. He eventually decided on fish, mainly because the teeth were smooth and lacked denticles. However, in 2013 Sues and Averianov noticed that these teeth did sport denticles, not unlike those of Richardoestesia isosceles, but rather than assign them there—along with dozens more from the Khodzhakul and Bissekty Formations—they chose to keep Nesov's epithet, and so Richardoestesia asiatica — "of Asia" — was born.
• C.W. Gilmore (1924) "A new coelurid dinosaur from the Belly River Cretaceous of Alberta".
• P.J. Currie, K.J. Rigby and R.E. Sloan (1990) "Theropod teeth from the Judith River Formation of southern Alberta, Canada".
• J.T. Sankey (2001) "Late Campanian southern dinosaurs, Aguja Formation, Big Bend, Texas".
• A Prieto-Marquez, R Gaete, A Galobart and L Ardevol (2010) "A Richardoestesia-like theropod tooth from the Late Cretaceous foredeep, south-central Pyrenees, Spain".
• D.W. Larson and P.J. Currie (2013) "Multivariate Analyses of Small Theropod Dinosaur Teeth and Implications for Paleoecological Turnover through Time".
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To cite this page:
Atkinson, L. "RICHARDOESTESIA :: from DinoChecker's dinosaur archive".
›. Web access: 29th Mar 2017.