The Snow Hill Island Formation is an

Early Maastrichtian The Maastrichtian () is, in the ICS geologic timescale, the latest age (uppermost stage) of the Late Cretaceous Epoch or Upper Cretaceous Series, the Cretaceous Period or System, and of the Mesozoic Era or Erathem. It spanned the interval fro ...

geologic

formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondar ...

found on

James Ross Island James Ross Island is a large island off the southeast side and near the northeastern extremity of the Antarctic Peninsula, from which it is separated by Prince Gustav Channel. Rising to , it is irregularly shaped and extends in a north–south ...

James Ross Island group The James Ross Island group is a group of islands located close to the northeastern tip of the Antarctic Peninsula. The largest islands in the group are James Ross Island, Snow Hill Island, Vega Island, and Seymour Island. The islands lie to ...

Antarctica Antarctica () is Earth's southernmost and least-populated continent. Situated almost entirely south of the Antarctic Circle and surrounded by the Southern Ocean, it contains the geographic South Pole. Antarctica is the fifth-largest contine ...

. Remains of a

paravian Paraves are a widespread group of theropod dinosaurs that originated in the Middle Jurassic period. In addition to the extinct dromaeosaurids, troodontids, anchiornithids, and possibly the scansoriopterygids, the group also contains the aviala ...

theropod Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally c ...

Imperobator ''Imperobator'' ("powerful warrior") is a genus of paravian theropod that lived during the Maastrichtian stage of the Late Cretaceous period in what is now Antarctica. It contains a single species, ''I. antarcticus'', recovered from the Snow Hi ...

antarcticus''Ely & Case, 2019 have been recovered from it, as well as the

elasmaria Elasmaria is a clade of ornithopods known from Cretaceous deposits in South America, Antarctica, and Australia that contains many bipedal ornithopods that were previously considered "hypsilophodonts".Madzia, Daniel; Boyd, Clint A.; Mazuch, Marti ...

n ornithopods '' Trinisaura santamartaensis'', ''

Biscoveosaurus This list of informally named dinosaurs is a listing of dinosaurs (excluding Aves; birds and their extinct relatives) that have never been given formally published scientific names. This list only includes names that were not properly published ...

'' and ''

Morrosaurus ''Morrosaurus'' is an extinct genus of herbivorous elasmarian dinosaur that lived in the late Cretaceous in Antarctica. The only known species is the type ''Morrosaurus antarcticus''. Discovery In 2002, the Argentine paleontologist Fernando ...

antarcticus'', the

ankylosauria Ankylosauria is a group of herbivorous dinosaurs of the order Ornithischia. It includes the great majority of dinosaurs with armor in the form of bony osteoderms, similar to turtles. Ankylosaurs were bulky quadrupeds, with short, powerful limbs. ...

n ''

Antarctopelta ''Antarctopelta'' (; meaning 'Antarctic shield') is a genus of ankylosaurian dinosaur, a group of large, quadrupedal herbivores, that lived during the Campanian stage of the Late Cretaceous period on what is now James Ross Island, Antarctica. '' ...

oliveroi'', and the shark ''

Notidanodon ''Notidanodon'' is an extinct genus of cow shark. Fossils ascribed to this genus are known from the Jurassic, Cretaceous, and Paleogene periods. The genus is known from every continent including Antarctica. Species The earliest occurrences of ...

'' sp. Alongside these described genera are also the remains of indeterminate

elasmosaurids Elasmosauridae is an extinct family of plesiosaurs, often called elasmosaurs. They had the longest necks of the plesiosaurs and existed from the Hauterivian to the Maastrichtian stages of the Cretaceous, and represented one of the two groups of p ...

,O'Gorman, 2012, p.2

lithostrotia Lithostrotia is a clade of derived titanosaur sauropods that lived during the Early Cretaceous and Late Cretaceous. The group was defined by Upchurch ''et al.'' in 2004 as the most recent common ancestor of ''Malawisaurus'' and ''Saltasaurus'' an ...

n titanosaurs and an indeterminate

pterosaur Pterosaurs (; from Greek ''pteron'' and ''sauros'', meaning "wing lizard") is an extinct clade of flying reptiles in the order, Pterosauria. They existed during most of the Mesozoic: from the Late Triassic to the end of the Cretaceous (228 to ...

. In the Herbert Sound Member of the Snow Hill Island Formation, bivalves,

ammonite Ammonoids are a group of extinct marine mollusc animals in the subclass Ammonoidea of the class Cephalopoda. These molluscs, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid and cuttlefish) ...

Fossil content

See also

References

Bibliography

Further reading