Richardoestesia
Named in honor of paleontologist Richard Estes, with the Latinized possessive form 'Richardoestesia' combining the first name Richard with the surname Estes.
Richardoestesia is a morphogenus of theropod dinosaur teeth, originally described from the Late Cretaceous of what is now Canada. Its two species are the type species R. gilmorei and R. asiatica from Uzbekistan, first named Asiamericana asiatica. A third, R. isosceles from Texas, is a nomen dubium. It has been used as a morphotaxon to describe other theropod teeth widely displaced in time and space from the type species. If all teeth assigned to the genus are truly reflective of the animals biology and taxonomic state (as some teeth go as far back as the Late Jurassic), it would have been one of the longest lasting dinosaur genera, perhaps also being the most widely distributed.
Under dispute
The type species, Richardoestesia gilmorei, rests on a pair of dentaries and is treated as valid (Currie and colleagues, 1990; Averianov and Sues, 2019). The isolated teeth referred to Richardoestesia across many formations and a long span of time probably represent several taxa (Larson and Currie, 2013; Averianov and Sues, 2019), so the name serves largely as a tooth form taxon. Its describers assigned it only to Maniraptora, family unknown, and it is retained provisionally at Dromaeosauridae incertae sedis.
Diagnosis
- Anterior mandibular teeth relatively straight with convex posterior outline in lateral view for distal half of tooth
- Posterior teeth relatively short and recurved
- Denticles shorter than other Judithian theropods, length 0.15 mm
- Up to five denticles per millimeter on posterior carina of mandibular teeth
- Curvature always present in proximal portion of tooth, contrasting with Maastrichtian Richardoestesia
Species (3)
Richardoestesia gilmorei Currie et al., 1990
Type species
Named for Charles Whitney Gilmore, the paleontologist who originally described the jaws as part of Chirostenotes pergracilis.
- Holotype
- NMC 343 , Canadian Museum of Nature
- Material
- Pair of dentaries with unerupted and germ teeth
- Horizon
- Dinosaur Park Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
- Locality
- Dinosaur Provincial Park, Alberta, Canada Currie and colleagues (1990) locate the holotype only to a township section.
Richardoestesia isosceles Sankey, 2001 Nomen dubium
From 'isosceles', for the isosceles-triangle outline of the tooth crown in lateral view.
- Holotype
- LSUMG 489:6238 , Louisiana State University Museum of Natural Science (LSUMNS)
- Material
- An isolated tooth.
- Horizon
- Aguja Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
- Locality
- Talley Mountain microsites (VL-489), Big Bend National Park, Texas, United States
Richardoestesia asiatica (Nessov, 1995)
First named as Asiamericana asiatica
From Latin asiatica ("Asian"), for its occurrence in the Asian part of the ancient continent Asiamerica.
- Holotype
- CCMGE 460/12457 , F.N. Chernyshev Central Museum of Geological Exploration
- Material
- An isolated tooth.
- Horizon
- Bissekty Formation, Turonian, Late Cretaceous , 93.9–89.8 million years ago
- Locality
- CBI-14, Dzharakuduk, Navoiy, Uzbekistan
- Diagnosis
-
- Mesial carina fully serrated on most teeth, unlike R. gilmorei.
- No interdenticular sulci, unlike R. gilmorei.
- Denticle size varies sporadically along the carinae on most teeth.
- A large area lacking enamel on the central part of the crown base on most teeth.
Synonyms of the genus
| Name | Type | Reason |
|---|---|---|
| Asiamericana | junior subjective | Sues and Averianov (2013) referred its type species, Asiamericana asiatica Nessov, 1995, to Richardoestesia after finding denticles on the holotype tooth. |
References
-
Currie, P. J.; Rigby, J. K.; Sloan, R. E. (1990). Theropod teeth from the Judith River Formation of southern Alberta, Canada. Dinosaur Systematics: Perspectives and Approaches (Carpenter, K.; Currie, P. J., eds.) 107-126. Cambridge University Press, Cambridge. doi:10.1017/cbo9780511608377.011
Erects the species and gives the holotype horizon as the "Judith River (Oldman) Formation, Dinosaur Provincial Park, Alberta".
currie1990a -
Larson, D. W.; Currie, P. J. (2013). Multivariate Analyses of Small Theropod Dinosaur Teeth and Implications for Paleoecological Turnover through Time. PLOS ONE 8(1): e54329. Public Library of Science (PLoS). doi:10.1371/journal.pone.0054329
Treated Richardoestesia as a tooth morphotype rather than a natural taxon.
larson2013a -
Sankey, J. T. (2001). Late Campanian southern dinosaurs, Aguja Formation, Big Bend, Texas. Journal of Paleontology 75(1): 208-215. Cambridge University Press (CUP). doi:10.1666/0022-3360(2001)075<0208:LCSDAF>2.0.CO;2
Erects Richardoestesia isosceles on an isolated tooth (LSUMG 489:6238) from the Aguja Formation of Big Bend, Texas.
sankey2001a -
Averianov, A. O.; Sues, H. D. (2019). Morphometric analysis of the teeth and taxonomy of the enigmatic theropod Richardoestesia from the Upper Cretaceous of Uzbekistan. Journal of Vertebrate Paleontology 39(3): e1614941. Informa UK Limited. doi:10.1080/02724634.2019.1614941
Places the R. gilmorei holotype in the Campanian Dinosaur Park Formation, revises the diagnosis of R. asiatica, and treats R. isosceles as a nomen dubium.
averianov2019b -
Sues, H. D.; Averianov, A. (2013). Enigmatic teeth of small theropod dinosaurs from the Upper Cretaceous (Cenomanian–Turonian) of Uzbekistan. Canadian Journal of Earth Sciences 50(3): 306-314. doi:10.1139/e2012-033
Transfers Asiamericana asiatica to Richardoestesia, noting that the holotype tooth has fine denticles.
sues2013a -
Nessov, L. A. (1995). Dinozavri severnoi Yevrazii: Novye dannye o sostave kompleksov, ekologii i paleobiogeografii [Dinosaurs of northern Eurasia: new data about assemblages, ecology, and paleobiogeography]. Institute for Scientific Research on the Earth's Crust, St. Petersburg State University, St. Petersburg 1-156.
Erects Asiamericana asiatica on three isolated teeth from the Bissekty Formation.
nessov1995a