Rhynchonella decorata Brachiopod Fossil Seashell Brachiopoda Invertebrata Mesozoic Jurassic Collection (1)

Description

Origin : France (Ardennes)

Geological era : Middle Jurassic (Bajocian)

Age : 170 million of years

Size : 18 gr - mm 30 x 26 x 22

Brachiopod Marine Fossil Sea Shell mm 30 x 26 x 22 gr 18 Rhynchonella (Isjuminella) decorata Benthic Sessile Invertebrata Extinct Prehistoric Brachiopods Mesozoic Jurassic Collecting Paleontology Museum.

Pleasant fossil find of Brachiopoda Rhynconellidae from the Middle Jurassic of Ardenne in France, representative collecible specimen of good quality well preserved, with clear details of the triangular shell's shape of the unequal dorsal and ventral valves and the longitudinal striae of the ribs.
Only a piece, as in photos.

Rhynchonella is an extinct genus of brachiopods found in the fossiliferous strata from the Silurian to the Eocene throughout the world.
It was a stationary epiphaunal suspensory invertebrate.
These articulated brachiopods long from 1.75 to 3.75 cm are characterized by a triangular shell with a spherical profile, marked ribs, a curved hinge line and a small umbo. The anterior border shows a tongue-shaped projection.
About forty extinct species are known.
Syn. Isjuminella decorata.

The phylum of Brachiopoda consists of marine Invertebrates, benthic, sessil, sospensivorous and with bilateral symmetry.
The plane of symmetry is perpendicular to the commissure of the valves, which are divided into a peduncular valve (or ventral) and a brachial valve (or dorsal), generally smaller. They are inequivalves and equilateral.
They look, similar to the phylum of bivalve molluscs, is simply due to convergent evolution, having no direct relationship with them.
Nowadays these animals are scarce because they live in "refuge areas", ie areas with low population and competition. They were however very common in the Paleozoic, then, following the mass extinction at the Permian-Triassic, have migrated into deeper waters.