Borealonectes is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of rhomaleosaurid

Rhomaleosauridae

Rhomaleosauridae is a family of extinct reptiles in the Plesiosauria order. It includes the Macroplata, Maresaurus, Rhomaleosaurus, Yuzhoupliosaurus and Meyerasaurus genera....

 pliosaur

Pliosaur

Pliosauroidea is an extinct clade of marine reptiles. Pliosauroids, also commonly known as pliosaurs, are known from the Jurassic and Cretaceous Periods. The pliosauroids were short-necked plesiosaurs with large heads and massive toothed jaws. These swimming reptiles were not dinosaurs but distant...

oid, a type of plesiosaur

Plesiosaur

Plesiosauroidea is an extinct clade of carnivorous plesiosaur marine reptiles. Plesiosauroids, are known from the Jurassic and Cretaceous Periods...

. Its fossils were found in the Callovian

Callovian

In the geologic timescale, the Callovian is an age or stage in the Middle Jurassic, lasting between 164.7 ± 4.0 Ma and 161.2 ± 4.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the Oxfordian....

-age (Middle Jurassic

Middle Jurassic

The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from 176-161 million years ago. In European lithostratigraphy, rocks of this Middle Jurassic age are called the Dogger....

, about 165-161 million years ago) Hiccles Cove Formation

Hiccles Cove Formation

The Hiccles Cove Formation is a Mesozoic geologic formation. Plesiosaur remains are among the fossils that have been recovered from its strata....

 of Melville Island, Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

, one of the islands in the Canadian Arctic Archipelago

Canadian Arctic Archipelago

The Canadian Arctic Archipelago, also known as the Arctic Archipelago, is a Canadian archipelago north of the Canadian mainland in the Arctic...

. It is based on

Holotype

A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...

 a skull, neck vertebrae, and the right forelimb of one individual. Named in 2008 by Sato and Wu, Borealonectes is one of the few plesiosaurs known from the Jurassic

Jurassic

The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

 of North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, and the first marine reptile

Marine reptile

Marine reptiles are reptiles which have become secondarily adapted for an aquatic or semi-aquatic life in a marine environment.The earliest marine reptiles arose in the Permian period during the Paleozoic era...

 from the Canadian Arctic with a well-preserved skull.