Grossaspis

Grossaspis Temporal range: Middle Devonian (Givetian),[1] 387.95–382.31 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Reconstruction of Grossaspis carinata
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	†Placodermi
Order:	†Antiarchi
Family:	†Pterichthyodidae
Genus:	†Grossaspis White & Moy-Thomas, 1940[3]
Species:	†G. carinata
Binomial name
†Grossaspis carinata Schlüter, 1887[2]
Synonyms[4]
Genus synonymy Ceraspis Schlüter, 1887, non Lepeletier & Serville, 1825 Cornaspis Whitley, 1940 Species synonymy Ceraspis hagenensis Schlüter, 1887

Grossaspis is a monotypic genus of antiarch placoderms known from the Givetian age of Eifel, Germany.[4] It is represented by the single species, Grossaspis carinata. They were likely marine bottom feeders, characterized by a steep dorsal crest and a greatly inclined head.[4]

Description

The genus has attributed to it a few trunk shield plates, including material from the anterior median dorsal plate, posterior median dorsal plate, and anterior ventro-lateral plate. The length of the trunk shield was, dorsally, of c. 9 cm. The anterior median dorsal plate was characterized by a protruding, tall, laterally compressed crest that tapers posteriously and continuously onto the posterior median dorsal plate. Dorsal lateral line grooves were not found present. The anterior ventro-lateral plate presented a rather short subcephalic component, resulting in a steep inclination of the head forward. The bone’s spongiosa (the internal spongy, meshlike component of the bone) was thick, regular and prismatic.[4]

Paleobiology

Like many antiarchs, Grossaspis were likely bottom feeders. However, while most antiarchs predominantly inhabited freshwater lakes and streams, Grossaspis were adapted to marine environments. Other known marine antiarchs include Gerdalepis and Lepadolepis.[4]

References

1. Lebedev, O. A.; Zakharenko, G. V. (2010-03-01). "Global vertebrate-based palaeozoogeographical subdivision for the Givetian-Famennian (Middle-Late Devonian): Endemism-cosmopolitanism spectrum as an indicator of interprovincial faunal exchanges". Palaeoworld. Middle Palaeozoic vertebrate biogeography, palaeogeography and climate (IGCP Project 491). 19 (1): 186–205. doi:10.1016/j.palwor.2010.03.002. ISSN 1871-174X.
2. Schlüter (1887). "Ueber Panzerfische und legte neue Arten aus dem rheinisch - westfälischen Devonvor". Sitzungsberichte der Niederrheinischen Gesellschaft für Natur- und Heilkunde in Bonn: 120 – via digital.zbmed.de.
3. White, Errol I.; Moy-Thomas, J. A. (1940-06-01). "XLVIII.—Notes on the nomenclature of fossil fishes.—Part I. Homonyms A-C". Annals and Magazine of Natural History. 5 (30): 502–507. doi:10.1080/00222934008527067. ISSN 0374-5481.
4. Denison, Robert (1978). Handbook of Paleoichthyology, Volume 2, Placodermi. New York: Gustav Fischer Verlage. p. 25. ISBN 9780895740274.