File:Ellipsocephalus hoffii fossil trilobites (Jince Formation, Middle Cambrian; vicinity of Jince, Stredocesky Region, Bohemia, Czech Republic) 3 (15259670651).jpg

Ellipsocephalus hoffii internal molds (center specimen is 23 mm long) from the Jince Formation (Middle Cambrian) of Bohemia.

The Middle Cambrian Jince Formation (pronounced “In-say”) of Bohemia is famous for its fossiliferous intervals that contain well-preserved trilobites. The Jince Formation’s trilobites have been documented in the literature since the 1700s.

One of the more common species in the Cambrian of Bohemia is Ellipsocephalus hoffii, first described & illustrated in 1823 by Ernst Friedrich Baron von Schlotheim as Trilobites Hoffii. It’s a rather plain-looking trilobite with a moderately effaced cephalon. Complete exoskeletons of this trilobite are abundant in certain intervals of the Jince Fm. The trilobites here are preserved as internal molds, often heavily stained with yellowish limonite, in greenish-gray silty mudshale.

Classification: Animalia, Arthropoda, Trilobita, Polymerida, Ellipsocephalidae

Stratigraphy: Ellipsocephalus hoffii zone (= lower Hydrocephalus lyelli zone), upper Jince Formation, upper Middle Cambrian. [note: Hydrocephalus lyelli was considered a subjective junior synonym of Hydrocephalus rotundatus by Kordule (1990)]

Locality: vicinity of Jince, Stredocesky Region, Bohemia, Czech Republic.

References Cited & Sources for Additional Info.:

Kordule, V. 1990. Rejkocephalus, a new paradoxid genus from the Middle Cambrian of Bohemia (Trilobita). Vestnik Ustredniho Ustavu Geologickeho 65: 55-60, 2 pls.

Schlotheim, E.F. 1823. Nachträge zur Petrefactenkunde, Zweyte Abtheilung. Gotha. 114 pp. 37 pls. [Trilobites Hoffii is described on pp. 30-31, 34, 85 & illustrated on pl. 22, figs. 2a, 2b.]

Šnajdr, M. 1958. Trilobiti českého středního kambria. Rozpravy Ústředního Ústavu Geologického 24. 280 pp. 46 pls. [Ellipsocephalus hoffii is described on pp. 88-92 & illustrated on pl. 7, figs. 1-8, pl. 8, figs. 1-7.]