Coelacanthus granulatus Agassiz, 1839

Taxonomy

Coelacanth

Kingdom: Animalia
Phylum: Chordata
Class: Coelacanthimorpha
Order: Coelacanthiformes L. S. Berg 1937
Family: Coelacanthidae Agassiz 1843
Genus: Coelacanthus
Species: Coelacanthus granulatus
Author Citation Agassiz, 1839

Geological Time Scale

Eon: Phanerozoic
Era: Paleozoic
Period: Permian
Sub Period: None
Epoch: Late
International Age: Wuchiapingian

Stratigraphy

Marl Slate Formation

Provenance

Acquired by: Purchase/Trade

Dimensions

Length: 9 cm

Location

Old Quarryington near Bowburn
County Durham
England
United Kingdom

• coelacanth
• coelacanthus
• durham county
• marl slate
• permian
• tff-oilshale-ch2430
• wuchiapingian

Comments

With 9cm body length a relatively small Coelacanthus granulatus.

Taxonomy from Fossilworks.org.

Diagnosis from Schaumberg 1978, p.195 (translated from German by oilshale): "Medium to large coelacanthid; moderately slender; head one-fifth of total body length. Endocranium partially ossified in anterior part, well ossified in middle part; basisphenoid with strong processus antoticus; no processus basipterygoidus; basal process of basisphenoid distinctly set off; pleurosphenoids present; ossifications on otico-occipital seem to be absent; parasphenoid broadened in its posterior part; separate vomeres not detectable. Posttemporalia and at least 5 extrascapularia developed; parieto-intertemporalia extend to extrascapularia, they are firmly attached to supratemporalia; parieto-intertemporalia not inseparably fused; frontal and dermosphenoticum form uniform bone stiick; both fronto-dermosphenotica not firmly fused; rostro-nasal zone yon numerous, mostly oval bone plates filled (3 pairs of nasalia, several rostralia resp. postrostralia; rearmost closes "fontanella" between nasalia; lateral boundary by stout laterorostralia and elongate tectal plates). Antorbitals absent; postorbitals weakly developed; squamosum and praeoperculum reduced to narrow ossifications around praeopercular sensory canal; small quadrato-jugal above median pterygoid bulge; operculum large and triangular; pterygoid with long, low, anterior limb and broad, vertical limb; maxillary dentition with pointed conical teeth on 6 praemaxillaries, on dermopalatinum and ectopterygoid, there also dental granulation. Large, posterior, nearly triangular coronoid clamped between praearticulate and angular, its exposed part appearing quadrangular; anterior, low coronoid with strong, conical teeth; other, small coronoids presumably between dentary and praearticular, concealed yon tooth-bearing, granulated dentary plates; upper margin of praearticular set with dense denticles; articular with two articulating pits for quadratum and symplecticum; pronounced processus retroarticularis. 
Gular plates with elongated median apex; urohyals, ceratohyals, hyomandibulars, ceratobranchialia (probably 4 pairs), and symplecticum present. Shoulder girdle composed of clavicle, cleithrum, separate extracleithrum, anocleithrum, supracleithrum; pectoral fin attached slightly below middle of body flank; pelvic girdle composed of narrow bony ridges widened like plates at distal end; ventral fins opposite to space between basal plates of both dorsalia; Basal plate of anterior dorsal fin oval to triangular; basal plate of posterior dorsal fin smaller, with forked projections directed anteriorly, traces of ossification in segmented fin shaft; basal plate of anal fin small and narrow; caudal fin with axial lobes; fin rays of all fins distally clearly articulated. 
Large, ossified swim bladder between scapular girdle and anal fin, at level of ventral fins is constricted in a muscular manner. 
Scales large and thin, longer than high; their klelner, exposed part covered with numerous, longitudinally directed tubercles." 
The diagnosis of the species corresponds to that of the genus.

Line drawing from Schaumberg 1978, p. 178:

Line drawing from Zhu et al. 2012, p. 2:

Cd, dorsal lobe of caudal fin; Cv, ventral lobe of caudal fin.

References:

L. Agassiz (1843) Recherches Sur Les Poissons Fossiles. Tome I (livr. 18). Imprimerie de Petitpierre, Neuchatel xxxii-188.
Schaumberg, G. (1978) Neubeschreibung von Coelacanthus granulatus Agassiz (Actinistia, Pisces) aus dem Kupferschiefer von Richelsdorf (Perm, W.-Deutschland). Paläontol. Z. 52, 169.. https://doi.org/10.1007/BF02987700.
H.-P. Schultze (2004) Mesozoic sarcopterygians. Mesozoic Fishes 3 - Systematics, Paleoenvironments and Biodiversity 463-492.
C. G. Diedrich (2009) A coelacanthid-rich site at Hasbergen (NW Germany): taphonomy and palaeoenvironment of a first systematic excavation in the Kupferschiefer (Upper Permian, Lopingian). Palaeobiodiversity and Palaeoenvironments 89:67-94.
Zhu M, Yu X, Lu J, Qiao T, Zhao W, Jia L. (2012) Earliest known coelacanth skull extends the range of anatomically modern coelacanths to the Early Devonian. Nat Commun. 10;3:772. doi: 10.1038/ncomms1764.