''Gerastos'' is a genus of
proetid trilobite in the family
Proetidae
Proetidae is a family of proetid trilobites. The first species appeared in the Upper Ordovician, and the last genera survived until the Middle Permian. However, if the closely related family Phillipsiidae is actually a subfamily of Proetidae, t ...
that lived between the
Pragian
The Pragian is one of three faunal stages in the Early Devonian Epoch. It lasted from 410.8 ± 2.8 million years ago to 407.6 ± 2.8 million years ago. It was preceded by the Lochkovian Stage and followed by the Emsian Stage. The most important La ...
and
Eifelian of the
Lower-Middle Devonian, spanning approximately 21 million years.
It was described by
Goldfuss in 1843.
Distribution
''Gerastos'' has been found in the Devonian of
Belgium,
Germany, the
Czech Republic and
Morocco.
Description
''Gerastos'' has
holochroal eyes situated to the side of its enlarged
glabella region of the
cephalon
Cephalon, Inc. was an American biopharmaceutical company co-founded in 1987 by pharmacologist Frank Baldino, Jr., neuroscientist Michael Lewis, and organic chemist James C. Kauer—all three former scientists with the DuPont Company. Baldino s ...
. The surface of the cephalon can be smooth or covered with pustules.
Length rarely exceeds 3 cm.
References
Proetidae
Proetida genera
Devonian trilobites of Africa
Devonian trilobites
{{proetida-stub