Borealestes

Borealestes Temporal range: Middle Jurassic Bathonian PreЄ Є O S D C P T J K Pg N ↓
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Order:	Therapsida
Suborder:	Cynodontia
Clade:	†Docodonta
Genus:	†Borealestes Waldman and Savage, 1972
Type species
†Borealestes serendipitus Waldman and Savage, 1972
Other Species
†B. mussetti Sigogneau-Russell, 2003

Borealestes was a genus of docodont from the Middle Jurassic, the first mammal from the Mesozoic found and named in Scotland.^[1] It was first discovered on the Isle of Skye near the village of Elgol. It was later found in other Middle Jurassic sites in England, where a second species was also named.

Discovery

The fossil of Borealestes serendipitus was discovered during field work on the Isle of Skye. The holotype is a fragment of jaw containing five molars and three premolars (BRSUG 20572)^[1] and there are several other jaw fragments known, all of them from The Kilmaluag Formation. The discoverers, Michael Waldman and Robert J. G. Savage carried out multiple trips to the island in search of mammals and other small fossils. They named Borealestes at the same time as a new species of Tritylodontid, Stereognathus hebridicus. The specific name derives from the Greek Boreas and Latin Boreal, meaning northern, the Greek listís meaning brigand, and the noun serendipity, relating to making a happy and unexpected discovery by accident.^[1]

After its discovery and naming, Borealestes was found in Kirtlington in England, and at Watton Cliff, both Middle Jurassic fossil sites.^[2]

In 2003, Borealestes mussetti was named from isolated molars found in the Bathonian aged Kirtlington Mammal bed of Oxfordshire, England.^[2] It differs from B. serendipitus in the details of cusps and ridges on the molar teeth. The species name mussetti was in honour of Dr. Frances Mussett, in recognition of their major participation in fossil excavation at Kirtlington. Additionally, molars referred to the type species B. serendipitus were found at both Kirtlington and the Watton Cliff locality in Dorset. Both of these localities belong to the Forest Marble Formation.

Appearance

Borealestes is only known from fragments of lower jaw and multiple isolated teeth. However, other members of Docodonta are small (shrew to rat sized) mammals. Borealestes is believed to be a basal member of Docodonta.^[3]

References