Ellipsocephalus
hoffii
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.
Ellipsocephalus hoffii internal molds on silty mudshale (field of view = 5.0
cm) from the Jince Formation (Middle Cambrian) of Bohemia.
Ellipsocephalus hoffii internal molds (left: 25 mm long; right:
23 mm long) from the Jince Formation (Middle Cambrian) of Bohemia.
Ellipsocephalus hoffii internal mold (~17.5 mm long) from the Jince
Formation (Middle Cambrian) of Bohemia.
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.]
Šnajdr, M. 1990. Bohemian Trilobites.
Prague. Geological Survey. 265 pp. [Ellipsocephalus hoffii
is described & illustrated on pp. 88-89]