Kyphosichthys
| Kyphosichthys | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
The holotype of Kyphosichthys grandei |
||||||||||||
| Temporal occurrence | ||||||||||||
| Anisium (Middle Triassic) | ||||||||||||
| 247.2 to 242 million years | ||||||||||||
| Locations | ||||||||||||
|
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Kyphosichthys | ||||||||||||
| Xu & Wu , 2011 | ||||||||||||
Kyphosichthys grandei is an extinct, primeval bony fish whose fossil remains, an almost complete holotype and a paratype were found in the Guanling Formation in the east of the Chinese province of Yunnan . They weredated to the anisium , a chronostratigraphic stage of the Middle Triassic ,with the help of key fossils from the group of the Conodonts .
The generic name is made up of "kyphos" and "ichthys" ( size : curved and fish) and refers to the curved back line, the type epitheton grandei was given in honor of the US-American biologist and paleontologist Lance Grande , who had a valuable Contribution to the research of ginglymodes and recently revalidated the bone organoids (Holostei).
features
The holotype of Kyphosichthys grandei has a total length of 9.6, a standard length of 7.6 and a body height of 5.5 cm. Besides Dapedium and Felberia, it is only the third high-backed fish known to date among the primeval Neopterygians . The body height is over 70% of the standard length. Immediately behind the head to in front of the dorsal fin, the back profile runs in a large hump. The greatest body height is reached at the level of the rear edge of the gill cover .
The dorsal fin and anal fin are far back, the latter is only half as long as the dorsal fin. The pelvic fins are much smaller than the pectoral fins. The forked caudal fin is heterocoic but externally almost symmetrical. Its upper lobe is scaled over a third of its length and is supported by ten of the 23 fin rays.
- Fin formula : dorsal fin i / 13; Anal fin i / 6; Pectoral fin 8; Ventral fin 6; Caudal fin 23.
- Scale formula : SL 29.
Way of life
Kyphosichthys grandei lived in the sea. From a comparison of the species with recent high-backed sea fish, such as the boar fish or the butterfly fish , one can conclude that Kyphosichthys grandei swam slowly but was very agile and probably occurred in an environment rich in structure, such as rock or coral reefs or in regions overgrown by seaweed .
Systematics
Kyphosichthys grandei is assigned to the bone organoids (Holostei) and belongs to the subgroup of Ginglymodi to which the recent bone pike (Lepisosteidae) also belong. Together with the semionotiformes and the gar-like (Lepisosteiformes) forms kyphosichthys grandei a Trichotomy that the Macrosemiiformes as a sister group faces.
source
- GuangHui Xu, FeiXiang Wu: A deep-bodied ginglymodian fish from the Middle Triassic of eastern Yunnan Province, China, and the phylogeny of lower neopterygians. In: Chinese Science Bulletin. Vol. 57, No. January 1, 2012, ISSN 0250-7862 , pp. 111-118, doi : 10.1007 / s11434-011-4719-1 .
Individual proof
- ↑ Lance Grande: An empirical study of synthetic pattern gars (Lepisosteiformes) and closely related species, based mostly on skeletal anatomy. The resurrection of Holostei (= Copeia. 10, 2010, 2A, Supplement Issue, ISSN 0045-8511 = American Society of Ichthyologists and Herpetologists. Special Publication. 6). Allen Press, Lawrence KS 2010.