Mucrospirifer

Mucrospirifer is a genus of extinct brachiopods in the class Rhynchonellata (Articulata) and the order Spiriferida. They are sometimes known as "butterfly shells".^[2] Like other brachiopods, they were filter feeders. These fossils occur mainly in Middle Devonian strata^[2] and appear to occur around the world, except in Australia and Antarctica.^[1][3]

Mucrospirifer Temporal range: Emsian-Tournasian[1] PreꞒ Ꞓ O S D C P T J K Pg N
Mucrospirifer mucronatus
Scientific classification
Kingdom:	Animalia
Phylum:	Brachiopoda
Class:	Rhynchonellata
Order:	†Spiriferida
Suborder:	†Delthyridina
Superfamily:	†Delthyridoidea
Family:	†Mucrospiriferidae
Genus:	†Mucrospirifer Grabau, 1931
Type species
Delthyris mucronatus Conrad, 1841
Species
See text

The biconvex shell was typically 2.5 cm long,^[2] but sometimes grew to 4 cm. The shell of Mucrospirifer has a fold, sulcus and costae. It is greatly elongated along the hinge line, which extends outward to form sharp points.^[2] This gives them a fin- or wing-like appearance. The apex area (umbo) of the pedicle valve contains a small fold for the pedicle.^[2] Mucrospirifer lived in muddy marine sediments, and were attached to the sea floor via the pedicle. The shell sometimes looks like two seashells stuck together.

Species

Mucrospirifer diluvianoides

Mucrospirifer thedfordensis

• Mucrospirifer albanensis
• Mucrospirifer arkonensis
• Mucrospirifer bouchardi
• Mucrospirifer diluvianoides
• Mucrospirifer grabaui
• Mucrospirifer medfordsis
• Mucrospirifer mucronatus (Conrad, 1841)
• Mucrospirifer paradoxiformis
• Mucrospirifer profundus
• Mucrospirifer prolificus
• Mucrospirifer refugiensis
• Mucrospirifer thedfordensis
• Mucrospirifer williamsi