Heptranchias howelli

Lore & Background

The largest tooth found at Trelde Næs measured 17.5 mm mesio-distally, 8.5 mm apico-basally, and 4.5 mm labio-lingually, with root heights ranging from 3 to 5 mm. Fossils of this species have been discovered in Eocene deposits of the La Meseta Formation in Antarctica, as well as in Canada (British Columbia), the United States (New Jersey, Oregon, Washington), and Miocene deposits of the Uitpa Formation in Colombia.

Reader's Guide

Heptranchias howelli is significant as an extinct representative of the sevengill shark lineage, providing evidence of the genus's wide geographic distribution during the Eocene and Miocene. Its fossil teeth, found across Europe, North America, South America, and Antarctica, indicate that these sharks inhabited diverse marine environments. The detailed descriptions of tooth morphology—such as the sigmoid cusp, serrations, and cusplet patterns—help paleontologists distinguish this species from related forms and track evolutionary changes within Heptranchias. The discovery of teeth in Denmark and Colombia, along with specimens from the United States and Canada, underscores the species' broad range. The largest tooth from Trelde Næs, measuring 17.5 mm, offers a glimpse into the size of these ancient sharks. Although the fossil record is limited to teeth, these remains are crucial for understanding the paleoecology and biogeography of extinct sharks. The species' existence from 37.2 to 20.43 Ma places it within a period of significant climatic and oceanic change, making it a valuable subject for studies of ancient marine life.

Did You Know?

• Upper lateral teeth have a long, acute, strongly sigmoid main cusp that is serrated.
• Fossils have been found in the La Meseta Formation on Seymour Island, Antarctica.
• An antero-lateral tooth and an upper lateral tooth were found in Faxe, Denmark in 2014.