''Microvenator'' (meaning "small hunter") is a genus of dinosaur from the

Early Cretaceous The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Pro ...

Cloverly Formation in what is now south central Montana. ''Microvenator'' was an

oviraptorosauria Oviraptorosaurs ("egg thief lizards") are a group of feathered maniraptoran dinosaurs from the Cretaceous Period of what are now Asia and North America. They are distinct for their characteristically short, beaked, parrot-like skulls, with or wit ...

n theropod. The holotype fossil is an incomplete skeleton, most likely a

juvenile Juvenile may refer to: *Juvenile status, or minor (law), prior to adulthood *Juvenile (organism) *Juvenile (rapper) (born 1975), American rapper * ''Juvenile'' (2000 film), Japanese film * ''Juvenile'' (2017 film) *Juvenile (greyhounds), a greyho ...

with a length of , and consequently, the adult size remains uncertain. ''Microvenator celer'' is primitive and may be the "sister taxon to all other oviraptorosaurs."Varricchio, D. J. 2001. Late Cretaceous oviraptorosaur (Theropoda) dinosaurs from Montana. pp. 42–57 in D. H. Tanke and K. Carpenter (eds.), Mesozoic Vertebrate Life. Indiana University Press, Indianapolis, Indiana.

Discovery

Barnum Brown Barnum Brown (February 12, 1873 – February 5, 1963), commonly referred to as Mr. Bones, was an American paleontologist. Named after the circus showman P. T. Barnum, he discovered the first documented remains of ''Tyrannosaurus'' during a career ...

collected the type specimen (AMNH 3041) in 1933 by a field party working for the

American Museum of Natural History The American Museum of Natural History (abbreviated as AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. In Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 26 inter ...

and he erroneously included '' Deinonychus'' teeth with the specimen. Because of this, Brown informally dubbed it "Megadontosaurus" ("big-toothed lizard"), Brown made illustrations of it, but never published the name, a fate shared with several other Cloverly Formation dinosaurs ('' Deinonychus'', ''

Sauropelta ''Sauropelta'' ( ; meaning 'lizard shield') is a genus of nodosaurid dinosaur that existed in the Early Cretaceous Period of North America. One species (''S. edwardsorum'') has been named although others may have existed. Anatomically, ''Saurop ...

'' and '' Tenontosaurus''). AMNH 3041 consists of a partial posterior skull, right dentary, 23 vertebrae, four ribs, the left coracoid, a partial left forelimb, a partial pelvis, and partial hindlimbs. It was not until 1970 that John Ostrom described the type specimen as part of his work on the Cloverly Formation, naming it ''Microvenator celer'' meaning "swift small hunter" due to its long legs. Ostrom originally theorized it was part of Othniel Marsh's Coeluridae due to features in the cervical vertebrae. Ostrom also referred a single tooth from the Yale Peabody Museum collection, YPM 5366, to this new species that likely belongs to '' Deinonychus''.OSTROM, JOHN H. ''Stratigraphy and Paleontology of the Cloverly Formation (Lower Cretaceous) of the Bighorn Basin Area, Wyoming and Montana''. Yale University Press, 2020, https://doi.org/10.2307/j.ctvxkn7tk. The illustrations that Brown had prepared were finally published in a detailed and exhaustive monograph by Mackovicky and Sues in 1998. They confirmed that ''Microvenator'' is an

n, and that it is the earliest known member of this group from North America.

Paleoenvironment

''Microvenator'' fossils are extremely rare, with only the type specimen described, likely due to lack of teeth and frail bones. ''Microvenator'' coexisted with notable dinosaurs like '' Deinonychus,

,'' and '' Acrocanthosaurus'' in the Himes Member of the Cloverly Formation.

References

Caenagnathids Early Cretaceous dinosaurs of North America Taxa named by John Ostrom Fossil taxa described in 1970 Cloverly fauna Paleontology in Montana {{Theropod-stub

Discovery

Paleoenvironment

See also

References