TY - JOUR
T1 - Exceptional appendage and soft-tissue preservation in a Middle Triassic horseshoe crab from SW China
AU - Hu, Shixue
AU - Zhang, Qiyue
AU - Feldmann, Rodney M
AU - Benton, Michael J
AU - Schweitzer, Carrie E
AU - Huang, Jinyuan
AU - Wen, Wen
AU - Zhou, Changyong
AU - Xie, Tao
AU - Lü, Tao
AU - Hong, Shuigen
PY - 2017/10/26
Y1 - 2017/10/26
N2 - Horseshoe crabs are classic "living fossils", supposedly slowly evolving, conservative taxa, with a long fossil record back to the Ordovician. The evolution of their exoskeleton is well documented by fossils, but appendage and soft-tissue preservation is extremely rare. Here we analyse details of appendage and soft-tissue preservation in Yunnanolimulus luopingensis, a Middle Triassic (ca. 244 million years old) horseshoe crab from Yunnan Province, SW China. The remarkable preservation of anatomical details including the chelicerae, five pairs of walking appendages, opisthosomal appendages with book gills, muscles, and fine setae permits comparison with extant horseshoe crabs. The close anatomical similarity between the Middle Triassic horseshoe crabs and their recent analogues documents anatomical conservatism for over 240 million years, suggesting persistence of lifestyle. The occurrence of Carcinoscorpius-type claspers on the first and second walking legs in male individuals of Y. luopingensis indicates that simple chelate claspers in males are plesiomorphic for horseshoe crabs, and the bulbous claspers in Tachypleus and Limulus are derived.
AB - Horseshoe crabs are classic "living fossils", supposedly slowly evolving, conservative taxa, with a long fossil record back to the Ordovician. The evolution of their exoskeleton is well documented by fossils, but appendage and soft-tissue preservation is extremely rare. Here we analyse details of appendage and soft-tissue preservation in Yunnanolimulus luopingensis, a Middle Triassic (ca. 244 million years old) horseshoe crab from Yunnan Province, SW China. The remarkable preservation of anatomical details including the chelicerae, five pairs of walking appendages, opisthosomal appendages with book gills, muscles, and fine setae permits comparison with extant horseshoe crabs. The close anatomical similarity between the Middle Triassic horseshoe crabs and their recent analogues documents anatomical conservatism for over 240 million years, suggesting persistence of lifestyle. The occurrence of Carcinoscorpius-type claspers on the first and second walking legs in male individuals of Y. luopingensis indicates that simple chelate claspers in males are plesiomorphic for horseshoe crabs, and the bulbous claspers in Tachypleus and Limulus are derived.
KW - Journal Article
U2 - 10.1038/s41598-017-13319-x
DO - 10.1038/s41598-017-13319-x
M3 - Article (Academic Journal)
C2 - 29075039
SN - 2045-2322
VL - 7
SP - 14112
JO - Scientific Reports
JF - Scientific Reports
IS - 1
ER -