TY - JOUR
T1 - Starfish diversity in the Wenlock of England
AU - Herringshaw, Liam
AU - Thomas, Alan
AU - Smith, Michael
PY - 2007/9/1
Y1 - 2007/9/1
N2 - Although their record extends back to the Early Ordovician, the occurrence of fossil starfish (Echinodermata: Asteroidea) is dependent almost exclusively upon horizons of exceptional preservation. Thus, asteroids found in Silurian obrution deposits of the English Midlands and Welsh Borderlands are particularly significant to an understanding of the early diversity of the group. Six species are described here: Hudsonaster? carectum sp. nov. (Hudsonasteridae), from the lower part of the Lower Elton Formation; and, from the Much Wenlock Limestone Formation, the hudsonasterids Doliaster brachyactis gen. et sp. nov. and Siluraster? ketleyi (Spencer, 1916), the lepidasterids Lepidaster grayi Forbes, 1850 and Lepidactis wenlocki Spencer, 1918, and the palasterinid Palasterina orchilocalia sp. nov. Though few in number, they show a diverse range of body morphologies when compared with Ordovician taxa: L. wenlocki had long, slender rays when fully grown whereas D. brachyactis is the first asteroid with the short-rayed body form of extant cushion stars. Most distinctive of all is L. grayi, the earliest multiradiate taxon known, all complete specimens of which have 13 rays. This morphological variety is interpreted as indicating that by the Early Silurian starfish were exploiting a wide range of feeding habits and ecological niches.
AB - Although their record extends back to the Early Ordovician, the occurrence of fossil starfish (Echinodermata: Asteroidea) is dependent almost exclusively upon horizons of exceptional preservation. Thus, asteroids found in Silurian obrution deposits of the English Midlands and Welsh Borderlands are particularly significant to an understanding of the early diversity of the group. Six species are described here: Hudsonaster? carectum sp. nov. (Hudsonasteridae), from the lower part of the Lower Elton Formation; and, from the Much Wenlock Limestone Formation, the hudsonasterids Doliaster brachyactis gen. et sp. nov. and Siluraster? ketleyi (Spencer, 1916), the lepidasterids Lepidaster grayi Forbes, 1850 and Lepidactis wenlocki Spencer, 1918, and the palasterinid Palasterina orchilocalia sp. nov. Though few in number, they show a diverse range of body morphologies when compared with Ordovician taxa: L. wenlocki had long, slender rays when fully grown whereas D. brachyactis is the first asteroid with the short-rayed body form of extant cushion stars. Most distinctive of all is L. grayi, the earliest multiradiate taxon known, all complete specimens of which have 13 rays. This morphological variety is interpreted as indicating that by the Early Silurian starfish were exploiting a wide range of feeding habits and ecological niches.
KW - palaeoecology
KW - starfish
KW - asteroidea
KW - wenlock
KW - taxonomy
KW - silurian
KW - multiradiate
UR - http://www.scopus.com/inward/record.url?scp=34548801911&partnerID=8YFLogxK
U2 - 10.1111/j.1475-4983.2007.00699.x
DO - 10.1111/j.1475-4983.2007.00699.x
M3 - Article
SN - 1475-4983
SN - 1475-4983
SN - 1475-4983
SN - 1475-4983
SN - 1475-4983
SN - 1475-4983
SN - 1475-4983
VL - 50
SP - 1211
EP - 1229
JO - Palaeontology
JF - Palaeontology
ER -