Discovery of nature’s oldest ‘mother’

SHE is the oldest mother of any species ever found, a 380-million-year-old fish immortalised in a fossil while still attached to her offspring by an umbilical cord.

Dubbed “mother fish” by the scientists who discovered her in northwestern Australia, “Materpiscis attenboroughi” is not only an entirely new genus and species, but pushes back the first known case of live birth in the animal kingdom by some 200 million years.

The tail-first birthing process was probably similar to that of some species of sharks and rays living today, says the study, published yesterday in the British journal Nature.

“The discovery is certainly one of the most extraordinary fossil finds ever made, and changes our understanding of the evolution of vertebrates,” commented lead researcher John Long, head of science at Museum Victoria.

Long and his colleagues were particularly astounded to find such a sophisticated reproductive system so far back on the evolutionary clock.

“It shows us that live birth was occurring at the same time as egg laying, and that these mechanisms evolved together rather than sequentially,” explained co-author Kate Trinajstic, who together with Long found the fossil.

The existence of the embryo and umbilical cord within the specimen also provides the first-ever example of “internal fertilisation” — that is, sex with penetration, the study says.

About 25 centimetres (10 inches) long, “mother fish” belongs to an extinct group of vertebrates, known as placoderms, that thrived during the middle Palaeozoic Era some 420 to 350 million years ago. Often called the dinosaurs of the seas, they ruled the world’s lakes and oceans for almost 70 million years.

The new find, remarkably preserved in three dimensions, contains a single, intra-uterine embryo connected by a calcified umbilical cord.

Long and his colleagues named their find after pioneering naturalist Sir David Attenborough, who first discovered the Gogo site which during the Devonian Period was a 1400-kilometre coral reef off the Kimberley coast of northwest of Australia.


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