Live birth in the Devonian period

Date

2008

Authors

Long, John
Trinajstic, Kate
Young, Gavin
Senden, Timothy

Journal Title

Journal ISSN

Volume Title

Publisher

Macmillan Publishers Ltd

Abstract

The extinct placoderm fishes were the dominant group of vertebrates throughout the Middle Palaeozoic era, yet controversy about their relationships within the gnathostomes (jawed vertebrates) is partly due to different interpretations of their reproductive biology. Here we document the oldest record of a live-bearing vertebrate in a new ptyctodontid placoderm, Materpiscis attenboroughi gen. et sp. nov., from the Late Devonian Gogo Formation of Australia (approximately 380 million years ago). The new specimen, remarkably preserved in three dimensions, contains a single, intra-uterine embryo connected by a permineralized umbilical cord. An amorphous crystalline mass near the umbilical cord possibly represents the recrystallized yolk sac. Another ptyctodont from the Gogo Formation, Austroptyctodus gardineri, also shows three small embryos inside it in the same position. Ptyctodontids have already provided the oldest definite evidence for vertebrate copulation, and the new specimens confirm that some placoderms had a remarkably advanced reproductive biology, comparable to that of some modern sharks and rays. The new discovery points to internal fertilization and viviparity in vertebrates as originating earliest within placoderms.

Description

Keywords

Keywords: copulation; Devonian; dominance; embryo; extinction; fish; new species; reproductive biology; type specimen; viviparity; article; copulation; Devonian; fertilization; fish; live birth; Masterpiscis attenboroughi; nonhuman; priority journal; shark; umbilic

Citation

Source

Nature

Type

Journal article

Book Title

Entity type

Access Statement

License Rights

DOI

10.1038/nature06966

Restricted until

2037-12-31