Sexual dimorphism within the stem-group arthropod Isoxys volucris from the Sirius Passet Lagerstätte, North Greenland

Nielsen, M.L.; Rasmussen, J.A.; Harper, D.A.T.

Sexual dimorphism within the stem-group arthropod Isoxys volucris from the Sirius Passet Lagerstätte, North Greenland

Nielsen, M.L.; Rasmussen, J.A.; Harper, D.A.T.

Authors

M.L. Nielsen

J.A. Rasmussen

Professor David Harper david.harper@durham.ac.uk
Emeritus Professor

Abstract

Morphometric analyses carried out on 126 specimens of the early Cambrian (Cambrian Series 2, Stage 3) stem-group arthropod Isoxys volucris from North Greenland reveal a bimodal distribution, where Morphogroup A is characterised by a significantly wider doublure than Morphogroup B. The dimorphism is interpreted as intraspecific variation related to gender (sexual dimorphism), where the relative numbers of individuals within the two morphogroups are equal (ratio 1:1). The discovery of established sexual dimorphism in Isoxys may have implications for the taxonomic discrimination of other stemgroup arthropods within the morphologically diverse and disparate animals of the early Cambrian.

Citation

Nielsen, M., Rasmussen, J., & Harper, D. (2017). Sexual dimorphism within the stem-group arthropod Isoxys volucris from the Sirius Passet Lagerstätte, North Greenland. Bulletin of the Geological Society of Denmark, 65, 47-58

Journal Article Type	Article
Acceptance Date	May 5, 2017
Online Publication Date	Jul 5, 2017
Publication Date	Jul 5, 2017
Deposit Date	Jul 5, 2017
Publicly Available Date	Jul 31, 2017
Journal	Meddelelser fra Danske Geologisk Forening.
Print ISSN	0011-6297
Electronic ISSN	2245-7070
Publisher	Geological Society of Denmark
Peer Reviewed	Peer Reviewed
Volume	65
Pages	47-58
Publisher URL	http://2dgf.dk/publikationer/bulletin/bulletin-volume-65-2017/