Africanaspis is a genus of armour plated (placoderm) fish, only known from the Late
Devonian (360 million year old) Waterloo Farm lagerstätten of South
Africa. It was first named, in 1997, on
the basis of isolated plates representing only three of the trunk armour
plates, of a single species (Africanaspis
doryssa).
Ongoing excavation of
shale rescued from Waterloo Farm, by Dr Rob Gess, who found the original
material, has since then produced far more complete material. In a paper
published in PLOS One on 5th April 2017, by Dr Rob Gess of the
Albany Museum and Rhodes University and Professor Kate Trinajstic of Curtin
University, reconstructions of the entire head and body armour of this
extraordinary fish are revealed. Incredibly though that’s not where it ends –
in several specimens there are also compressions preserved of the unarmoured
tails that protruded behind the armoured body. This soft unarmoured portion of
the body is completely unknown in the vast majority of armour plated fish.
The authors
furthermore reveal that a second, more robust species which they named Africanaspis edmountaini also inhabited the Waterloo Farm lagerstätten
lagoon.
Specimens represent
fish of a range of sizes. Although adult Africanaspis
doryssa were between 20 and 30 centimetres long, one minute specimen was
less than 3 centimetres long. Its large eyes suggest that it was newly hatched
or born. This range of sizes indicate that Africanaspis spent its entire life around the coastal
lagoonal lake that is represented at Waterloo Farm. This differs from the
lifestyle of coelacanths previously described from the same site, which are
only known from juveniles, indicating that they used the ancient estuary
exclusively as a breeding nursery.
Link to paper online:
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0173169
