John A. Long describes his Eureka! moment, which he had while examining an extraordinarily preserved fish fossil he and his team found at the site of the tropical shallow-sea Devonian Gogo reef in now-dry northwestern Australia [1-3]. The excitement came with the discovery of a fossilized umbilical cord belonging to an embryo in the ancient fish. After in-depth analysis using scanning electron microscopy (SEM) the researchers soon were convinced that they were studying an 375-million-year-old expectant mother fish and the oldest vertebrate embryo on record. They named the newly discovered ptyctodontid placoderm Materpiscis attenboroughi, meaning “Attenborough's mother fish,” after the British nature presenter David Attenborough, who introduced the Gogo fossil sites to the world in the 1979 documentary series Life on Earth [1].
The fossilized Gogo specimen is critical in dating the beginning of copulation, fertilization, childbearing and birth giving. Is it time to celebrate 375 million years of sexual intercourse or is the origin of this form of intimate vertebrate reproduction going even further back in time? And what was (is) the evolutionary advantage over spawning—still practiced by many aquatic animals today?
References and fun by exploring more
[1] John A. Long: Dawn of the Deed. Scientific American January 2011, 304 (1), pp. 34-39. Excerpt.
[2] Sarah Clarke: Aussie scientists find world's oldest fossil mum. ABC News.
[3] J. A. Long, K. Trinajstic, G. C. Young and T. Senden: Live birth in the Devonian period. Nature 29 May 2008, 453, pp. 650-652.
DOI: 10.1038/nature06966.
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