Qianodus
| Qianodus Temporal range:
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|---|---|
| Tooth whorl of Qianodus duplicis. Volume rendering of the holotype specimen shown in lateral view with colour coded primary (yellow and blue) and accessory (red) teeth. | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Chondrichthyes |
| Genus: | †Qianodus Andreev et al. 2022 |
| Species: | †Q. duplicis
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| Binomial name | |
| †Qianodus duplicis Andreev et al. 2022
| |
Qianodus (from the Chinese: 黔, 'Qian', the ancient name for Guizhou and the Greek: ὀδούς, odus, 'tooth') is a jawed vertebrate genus that is based on disarticulated teeth from the lower Silurian (Aeronian, c. 439 Myr) of China. The type and only species of Qianodus, Q. duplicis, is known from compound dental elements called tooth whorls, each consisting of multiple tooth generations carried by a spiral-shaped base. The tooth whorls of Qianodus represent the oldest unequivocal remains of a toothed vertebrate, predating previously recorded occurrences by about 14 million years. The specimens attributed to the genus come from limestone conglomerate beds of the Rongxi Formation exposed near the village of Leijiatun, Guizhou Province, China. These horizons have been interpreted as tidal deposits1 that form part of the shallow marine sequences of the Rongxi Formation.