Acanthodian,onychodontid and osteolepidid fish from the middle-upper Taemas Limestone (Early Devonian), Lake Burrinjuck,New South Wales

A meagre ischnacanthid acanthodian fauna, known from fragmentary dentigerous jawbones from Lake Burrinjuck, Yass district, New South Wales, consists of three taxa: Taemasacanthus narrengullenensis, Taemasacanthus cooradigbeensis and an indeterminate ischnacanthid. The fossils are from three Early Devonian (Emsian) units at Taemas: the Bloomfield Limestone Member, the Currajong Limestone Member and the Warroo Limestone Member, which constitute the middle-upper parts of the Taemas Limestone (Murrumbidgee Group); and from Unit 6 of the ‘Upper Reef formation’ at Wee Jasper. Whereas ischnacanthid acanthodian remains are increasingly rarer in the higher levels of the Taemas Limestone, remains of onychodontid and osteolepidid fishes are relatively abundant; Onychodus yassensis sp. nov., Onychodus sp. and isolated osteolepidid teeth are locally common.     

Redescription of Parexus recurvus,an Early Devonian acanthodian from the Midland Valley of Scotland

Parexus Agassiz was one of the first Early Devonian ‘spiny sharks’ to be described. The genus is readily recognized by the large size and ornament of its anterior dorsal fin spine. Although two species were erected, reappraisal of all known specimens indicate they should be synonymized in the type species Parexus recurvus. Farnellia tuberculata Traquair, originally described as a vertebral column, is actually tooth rows of jaw dentition, and is also now considered to be a junior synonym of P. recurvus. Parexus has a perichondrally ossified scapulocoracoid of typical acanthodian shape, and diagnostic features of the family Climatiidae, but has distinctive scales comprising appositional growth zones that closely resemble those of the putative stem chondrichthyan Seretolepis elegans Karatajute-Talimaa.     

A new Late Devonian acanthodian fish from the Hunter Formation near Grenfell,New South Wales

The ischnacanthid acanthodian Grenfellacanthus zerinae gen. et sp. nov. is described on the basis of two large jaw bones from the Late Devonian (late Famennian) Hunter Formation, near Grenfell, N.S.W. The new species is the youngest known ischnacanthid, and the largest ischnacanthid from Gondwana. As for many ischnacanthids, the structure of the jaws and teeth indicate that Grenfellacanthus was probably an ambush predator.     

Late Silurian vertebrate microfossils from the Carnarvon Basin,Western Australia

Burrow, C.J., Turner, S., Trinajstic, K. &; Young, G.C., 27 February 2019. Late Silurian vertebrate microfossils from the Carnarvon Basin, Western Australia. Alcheringa 43, 204–219. ISSN 0311-5518.

A core sample from the offshore Pendock 1A well, Carnarvon Basin, Western Australia yielded microvertebrate residues at an horizon in the lower part of the Hamelin Formation, dated as late Silurian, ? Ludlow, based on associated conodonts. The fish fauna comprises loganelliiform thelodont scales, the ? stem gnathostome Aberrosquama occidens nov. gen. et sp., the acanthodian Nostolepis sp. aff. N. alta, and the ? stem osteichthyan Andreolepis sp. aff. A. petri. Because of the paucity of the material, and some differences between the Pendock scales and those of established species, a precise age can not be confirmed; however, the composition of the fauna at generic level most closely resembles that of late Silurian (Ludlow) assemblages from northern Eurasia.

Carole J. Burrow* [carole.burrow@gmail.com], Geosciences, Queensland Museum, Hendra QLD 4011, Australia; Susan Turner [palaeoich@yahoo.com], Geosciences, Queensland Museum, Hendra QLD 4011, Australia; Kate Trinajstic [k.trinajstic@curtin.edu.au], School of Molecular and Life Sciences, Curtin University, Perth, WA 6102, Australia; Gavin C. Young [gavin.young@anu.edu.au], Research School of Physics and Engineering, Australian National University, Canberra, ACT 2000, Australia.