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Anatomical distinctions of the Mesozoic lingulide brachiopods

100%

Biernat G., Emig C. C.

Acta Palaeontologica Polonica

1993

tom 38

nr 1-2

1-20

The long held view that Lingula represents an extremely bradytelic lineage is questioned. Examination of Mesozoic lingulides has shown that they significantly differ from their Recent relatives Lingula and Glottidia in having longer lophophoral cavities, shorter ventral canals, better developed posterior adductor muscles, and less acute umbones. Morphological characters of the shell interior are needed to identify members of the Lingulidae, not solely external shell characteristics. The apparent evolutionary tendency towards a reduction of the volume of the lophophoral cavity contradics the traditional view that the ‘living fossil’ Lingula has survived without significant morphological change since the Paleozoic. Actually the today living lingulide genera probably arose in the early Cenozoic. A new inarticulate brachiopod genus, Lingularia is introduced, with three new species. Middle Triassic L. siberica, Middle Jurassic L. similis, and Cretaceous L. smirnovae.

The brachiopod Lingula in the Middle Miocene of the Central Paratethys

100%

Emig C. C., Bitner M. A.

Acta Palaeontologica Polonica

2005

tom 50

nr 1

In the Middle Miocene deposits of the Central Paratethys, lingulides, because of their low taphonomic potential, are very rare and difficult to identify. Two species of Lingula, L. dumortieri Nyst, 1843 and L. dregeri Andreae, 1893, have been recorded from the Badenian (Middle Miocene) of Poland. Re−examination of the specimens has shown that none of them can be referred to Lingula dumortieri (now Glottidia dumortieri). The rounded outline of the scar of the posterior adductor muscle and the lack of the septa indicate that all the specimens must be referred to the genus Lingula. Their valves appear to be slightly more convex than in other species of Lingula and closely resemble the Recent L. tumidula Reeve, 1841. We assign all the specimens of Lingula found in the Miocene of Poland to L. dregeri. Because our specimens are juveniles and some are broken we cannot adequately redescribe this species. Lingula dregeri was distributed in the Middle Miocene of the Central Paratethys (Austria, Poland, Ukraine, Romania), while Glottidia dumortieri occurs in the Pliocene of Northern Europe (Atlantic Province).

Ograniczanie wyników

2 Acta Palaeontologica Polonica

2 Emig C. C.

1 Biernat G.

1 Bitner M. A.

1 2005

1 1993

Wyniki wyszukiwania

Anatomical distinctions of the Mesozoic lingulide brachiopods

The brachiopod Lingula in the Middle Miocene of the Central Paratethys