Hindeodus parvus
| Hindeodus parvus | ||||||||
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| Temporal occurrence | ||||||||
| Lower Triassic ( Indusium ) | ||||||||
| 251 million years | ||||||||
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| Systematics | ||||||||
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| Scientific name | ||||||||
| Hindeodus parvus | ||||||||
| Kozur & Pjatakova , 1975 |
Hindeodus parvus is a species of extinct conodonts (Conodonta) that was first found in the fossil- bearing rocks of Meishan in Changxing Countyin the Chinese province of Zhejiang .
Like other conodonts, Hindeodus parvus serves as a guide fossil . Its first appearance in the stratigraphic sequence of the sedimentary rocks documents the beginning of the geological section of the Indusian . The Indusium is the oldest chronostratigraphic stage of the Triassic and thus the oldest specimens of this conodont in the fossil record stand for the transition from the youngest Permian ( Lopingian ) to the oldest Lower Triassic and thus for the beginning of the Mesozoic ( Mesozoic Era).
features
The conodont apparatus of Hindeodus parvus , as in all species of the genus, consists of six different elements. The platform elements (Pa) are small with a large, slender and upright, slightly backward-facing or curved tooth, followed by 4 to 9 significantly smaller teeth. Two morphotypes can be distinguished, although numerous transitional forms occur between them. The smaller teeth in Morphotype 1 are slimmer and all about the same size. The rear part of the element drops off significantly here and has no teeth. In Morphotype 2, the teeth are slightly longer with an upper edge sloping slightly from the tip. The rear third of the platform element is covered with numerous small, inclined teeth. The branch shape elements (r) have a relatively short, high bar for Hindeodus . In the Sb element, in contrast to all other Hindeodus species, the sharp inward curvature of the anterior bar also includes the tip and occasionally the first tooth of the rear bar.
distribution
Hindeodus parvus was common throughout Tethys .
literature
- Yin Hongfu, Zhang Kexin, Tong Jinnan, Yang Zunyi and Wu Shunbao: The Global Stratotype Section and Point (GSSP) of the Permian-Triassic Boundary. Episodes, 24, 2, Beijing 2001 ( PDF , illustration on p. 105).
- Heinz Kozur : Some remarks to the conodonts Hindeodus and Isarcicella in the latest Permian and earliest Triassic. Palaeoworld. 6, pp. 64-77, 1995 ( PDF ).