RT Journal Article
SR Electronic
T1 Anamorphic development and extended parental care in a 520 million-year-old stem-group euarthropod from China
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 266122
DO 10.1101/266122
A1 Dongjing Fu
A1 Javier Ortega-Hernández
A1 Allison C. Daley
A1 Xingliang Zhang
A1 Degan Shu
YR 2018
UL http://biorxiv.org/content/early/2018/02/16/266122.abstract
AB Extended parental care (XPC) is a complex reproductive strategy in which progenitors actively look after their offspring up to – or beyond – the first juvenile stage in order to maximize their fitness. Although the euarthropod fossil record has produced several examples of brood-care, the appearance of XPC within this phylum remains poorly constrained given the scarcity of developmental data for Palaeozoic stem-group representatives that would link juvenile and adult forms in an ontogenetic sequence. Here, we describe the post-embryonic growth of Fuxianhuia protensa from the early Cambrian Chengjiang Lagerstätte, and show parental care in this stem-group euarthropod. We recognize fifteen distinct ontogenetic stages based on the number and shape of the trunk tergites, and their allocation between the morphologically distinct thorax and abdomen. Our data demonstrate anamorphic post-embryonic development in F. protensa, in which tergites were sequentially added from a posterior growth zone. A life assemblage consisting of a sexually mature F. protensa adult alongside four ontogenetically coeval juveniles, constitutes the oldest occurrence of XPC in the panarthropod fossil record. These findings provide the most phylogenetically basal evidence of anamorphosis in the evolutionary history of total-group Euarthropoda, and reveal a complex post-embryonic reproductive ecology for its early representatives.