Name: Illaenus
taurikornis
Trilobite
Order Corynexochida
Geologic
Time : Ordovician
Fossil Site:
71 mm
Location:
Asery
level, St. Petersburg region, Wolchow river, Russia
| The
morphology of Illaenus was being repeated throughout the world's vast
Ordovician shallows, despite the lack of anything but perhaps ancient
ancestral lineage (perhaps pre-Cambrian). This phenomena, known as
homoeomorphy, enabled trilobites to assume close appearance owing
to their independent adaptation in similar environments. The Illaenus
form (some call the tank), is highly convex. Because of homoeomorphy,
they are found on every continent. Of the 16 described species of
the Illaenus family coming from the St. Petersburg, Russia region
(Wolchow river) Illaenus taurikornis shown here is rare and exotic.
This awesome specimen is highly 3D, and the nasty genal spines are
free from matrix and swept back in a threatening angle, ostensibly
providing a sharp surprise to a would-be predator with the trilobite
enrolled. |
|
