A Museum Victoria team announced its latest and the most remarkable find on 29May-a 375 million-year-old fossil of placoderm fish with intact embryo and mineralized umbilical cord.The fossil, one of the most significant discoveries ever made by scientists, also happens to be thet of the worlds oldest known vertebrate mother.It provides the earliest evidence of vertebrate sexual reproduction, wherein the males(possessing clasping organs similar to modern sharks and rays) internally fertilized females.
This fossil has been named Materpiscis Attenboroughi, meaning "mother fish' in honor of Sir David Attenborough, who first drew attention to the significance of the Gogo sites in his 1979 series Life on Earth.Armorplated shark like fishes with no modern relatives a second placoderm specimen containing three embryos was found earlier in 1986 and only recently recognized. These embryos also provided the first data on their developmental biology ,indicating the early sequence of bone formation in the placoderms growth stages
An ultra fine CT scanner at the Australian National University heiped examine the old fossil in such an extraordinary stage of preservation.The team had also previously announced the first 3-D preserved muscle, nerve and circulatory tissues in a Devonian age(380million years old) fish in 2007 paper in biology Letters .Earlier in 2005 ,Museum Victoria expedition Western Australia led byDr John long made aswag of spectacular fossil discoveries including that of a complete fish Gogonasus showing unexpected features similar to early land animals.
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