Materpiscis would have been about long and had powerful crushing tooth plates to grind up its prey, possibly hard shelled invertebrates like clams or corals. Examination of the tail section of the holotype led to the discovery of the partially ossified skeleton of a juvenile
Materpiscis and the mineralised umbilical cord. The team published their findings in 2008. The juvenile
Materpiscis was about 25 percent of its adult size. The large size of the embryo relative to the mother indicates that the young of this fish were born well-formed, a strategy that may have evolved to counter predation from other larger fishes. The ptyctodontid fishes are the only group of placoderms to display
sexual dimorphism, where
males have clasping organs and
females have smooth pelvic fin bases. It had long been suspected that they reproduced using
internal fertilisation, but finding fossilised embryos inside both
Materpiscis and in a similar form also from Gogo,
Austroptyctodus, proved the deduction was true. ==In popular culture==