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|Morphology||Ecology and taphonomy||External Literature Search||Age range and collections|
Lingulata - Lingulida - Lingulidae
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If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.
|S. H. Chuang 1964 (Glottidia glauca)||Small species with thin, brittle, broad, cream-colored shells with gleaming smooth external surface except for the impres- sions of the large setae. Each shell valve is moderately arched and has subparallel sides which converge slightly and very gradually in the anterior two-thirds of its length. The anterior margin of the shell is curved in the young but truncate in later stages. On the inner surface at the posterior part of the ventral valve are two widely divergent laminae arranged symmetrically on either side of the sagittal plane with their anterior end midway between the sagittal plane and the lateral shell edge. A broad low median ridge lies inside the V-shaped area bounded by the laminae and extends posteriorly into the poste- rior third of this area. The inner surface of the dorsal shell valve is unknown.
|C. C. Emig and M. A. Bitner 2005||Ventral valve: umbonal region slightly acuteangled with a rather rounded beak and a subparallel pedicle groove that is not continuous with the inner valve side; anterior and median internal oblique muscles similarly elongate; posterior internal oblique muscle rounded; posterior adductor muscles centred over the septa; two oblique septa, widened and curved, the left septum slightly longer than that on the right and generally more arcuate; both septa originating posteriorly at the level of the pedicle groove edges. Dorsal valve: narrow dorso-central ridge at the level of the anterior oblique muscles; umbonal region slightly acute with a rather rounded beak. Anterior mantle canals oblique, curved forward concavely. Text-figure 3 is part of this diagnosis, mainly for the muscle arrangement and the disposition of the mantle canals and septa.|