Guide for the identification of archaeological sea sturgeon (<i>Acipenser sturio</i> and <i>A. oxyrinchus</i>) remains

Remains of sturgeons (Acipenser sturio and A. oxyrinchus) are regularly found on western European archaeological sites. The identification of these isolated bones should ideally be carried out with the aid of a comparative skeletal collection, consisting of modern specimens of different sizes. Because such reference material of sea sturgeons (A. sturio and A. oxyrinchus) is relatively rare and dispersed over many different museums and institutes, a practical guide is presented here as an aid to the identification of the most commonly found archaeological sturgeon remains. This guide, which is based on observations made on 64 individuals housed in 13 different natural history collections, should allow identifying most archaeological sturgeon remains from western European sites. Presented are the morphological characteristics of the bones of the skull roof and circumorbital region (posttemporal, dermopterotic, parietal, frontal, dermosphenotic, postorbital, jugal and supraorbital), bones of the braincase (parasphenoid), opercular series (subopercle and branchiostegals), the palatoquadrate and associated bones and lower jaw (palatopterygoid, dermopalatine and dentary), the hyoid and gill arches with the hyomandibula, the isolated skeletal elements from the pectoral girdle (clavicle, cleithrum and supracleithrum), the bones of the fin and fin supports (pectoral fin spine, fin rays and fulcra) and the dorsal, ventral, lateral and accessory scutes. For each element, descriptions and pictures are provided of modern and archaeological specimens. Regression equations allowing fish length reconstructions on the basis of single bone measurements are given for 14 elements and the scutes. Finally, criteria for species identification are provided. In the case of the dentary, dermopalatine and palatopterygoid, these are differences in shape of the skeletal elements, whereas for the dermal bones the external surface pattern is diagnostic when reconstructed fish length is over one meter

Inter- and intraspecific variation in the surface pattern of the dermal bones of two sturgeon species

Archaeological bone remains of sturgeon (Acipenser sturio/Acipenser oxyrinchus) from northwestern Europe are often identified to species on the basis of their surface morphology and then used to reconstruct the spatial distribution of the two species through time. The dermal bones of A.sturio are said to have an exterior surface pattern consisting of tubercles, while those of A.oxyrinchus are said to display alveoli. In the present paper, the validity of the surface pattern as a species-specific characteristic is critically assessed. To this purpose, dermal plates from modern, genetically identified museum specimens were studied and the surface morphology observed in a series of archaeological remains was compared with the genetic identifications obtained on these same remains. The analyses show that the surface pattern of dermal bones is related to the size of the individual, with the pattern of small A.oxyrinchus being similar to that of A.sturio. In addition, variations in the surface pattern among the bones of a single individual and within the same bone have been observed. These findings explain previous conflicting results between morphological and genetic identifications and allow the formulation of some recommendations for more accurate morphological identification of isolated archaeological sturgeon dermal bones

Het Woestijnegoed en het kasteel van Woestijne

status: publishe