Minicrania

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Minicrania
Temporal range: Lochkovian
Minicrania lirouyii.JPG
Reconstruction of M. lirouyii adult and juveniles
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Class: Placodermi
Order: Antiarchi
Genus: Minicrania
Zhu and Janvier, 1996
Type species
Minicrania lirouyii
Zhu and Janvier, 1996
Species
  • M. lirouyii
  • M. lissa Janvier and Phuong, 1999[1]

Minicrania ("small skull") is an extinct genus of tiny antiarch fish, with armor averaging up to about 2 centimetres (0.79 in) long, which lived during the Lochkovian epoch in Early Devonian Yunnan Province, China and northern Vietnam.

Anatomically, Minicrania bears a strong resemblance to the Yunnanolepiformids (i.e., Yunnanolepis and Chuchinolepis).[2] However, other anatomical features, especially the head-width ratios, separate it from the Yunnanolepiformids. Zhu and Janvier regard it as the sister taxon of the sinolepids and the Euantiarchi (i.e., the bothriolepids and the asterolepids), representing a transitional form between the Euantiarchi and the more primitive Yunnanolepiformids.

There are two recognized species. The type species, M. lirouyii, is found in Lochkovian-aged strata in Qujing, Yunnan, and is characterized by the presence of numerous tubercles covering the dermal surface of the armor. The specific name honors a Mr. Li Rou-yi, who assisted in collecting the first specimens. The second species, M. lissa,[1] is found in Lochkovian deposits in northern Vietnam, near the Chinese border. M. lissa's tubercles are comparatively very small and ill-defined, if present, hence the specific epithet "lissa" meaning "smooth." Otherwise, the armor is very similar, if not identical to that of M. lirouyi.

References[edit]

  1. ^ a b Janvier, P., Phuong, T.H (1999). "Les vertébrés (Placodermi, Galeaspida) du Dévonien inférieur de la coupe de Lung Cô-Mia Lé, province de Hà Giang, Viêt Nam, avec des données complémentaires sur les gisements à vertébrés du Dévonian du Bac Bo oriental.". Geodiversitas 21: 33–67. 
  2. ^ Zhu, Min; Philippe Janvier (March 1996). "A SMALL ANTIARCH, MINICRANIA LIROUYII GEN. ET SP. NOV., FROM THE EARLY DEVONIAN OF QUJING, YUNNAN (CHINA), WITH REMARKS ON ANTIARCH PHYLOGENY". Journal of Vertebrate Paleontology 16 (1): 1–15. doi:10.1080/02724634.1996.10011278.