Boreostemma is an extinct genus of glyptodonts from northern South America. Fossils assigned to the genus were first described as belonging to Asterostemma from southern South America, but have been placed in the new genus Boreostemma by Carlini et al. in 2008. The type species is B. pliocena. Fossils of Boreostemma have been found in the Honda Group of Colombia, in Peru and Venezuela.
Etymology
The genus name Boreostemma is a combination of stemma, taken from Asterostemma, and boreo is derived from borealis, meaning "northern", to distinguish the northern South American genus from the southern Asterostemma.[1]
Taxonomy
Boreostemma has been placed as closely related to the later Glyptodon and Glyptotherium. Cladogram after Barasoain et al. 2022:[2]
Locations of Boreostemma and Asterostemma fossil finds in South America Asterostemma B. acostae & B. gigantea B. pliocena (type) B. venezolensis Boreostemma sp.
The type speciesB. pliocena was described in 2008 by Carlini et al. based on 30 osteoderms palate fragment with M6-7 alveoli.[9] Fossils have been described from the type locality along the road to Tío Gregorio in the Codore Formation at the Lagerstätte of Urumaco.[10]
B. venezolensis was described as Asterostemma venezolensis in 1947 by George Gaylord Simpson,[20] based on most of the carapace and the anterior end of the lower jaw, including teeth.[21] Fossils have been uncovered from the Santa Inés Formation along the banks of the Güere River in the state of Anzoátegui in Venezuela.[22]
