A new placoderm fish of uncertain affinity from the Early–Middle Devonian Hatchery Creek succession at Wee Jasper, New South Wales

First Articulated Phyllolepid Placoderm from North America, with Comments on Phyllolepid Systematics

“…Howitt material was described as two species of Austrophyllolepis based on differing plate proportions (Long, 1984). This work supported Stensiö's assignment of the group to Placodermi, and provided the first cladistic analysis of the group demonstrating that they are a clade nested within Arthrodira, a view that has since been supported by other phylogenetic analyses (Goujet and Young, 2004;Dupret, 2004;Dupret and Zhu, 2008;Dupret et al, 2009;Hunt and Young, 2011).…”

“…They are now interpreted to be a distinct clade nested deeply within Arthrodira (Long, 1984;Dupret, 2004;Dupret and Zhu, 2008). The taxonomic stability of this classification is weak, however, due to current debate over the monophyly of the Arthrodira (Young, 2008;Hunt & Young 2011). The diagnosis of Phyllolepidae includes all forms with a single centronuchal plate that is as broad or broader than long (thus lacking paired central plates) and surrounded by five pairs of marginal dermal plates.…”

Asia–Gondwana connections indicated by Devonian fishes from Australia: palaeogeographic considerations

“…These are a very common component in all Devonian fish assemblages of East Gondwana, but neither wuttagoonaspids nor phyllolepids are known from the diverse younger Devonian fish assemblages in Asia. A new phylogenetic analysis (Hunt and Young 2011) failed to recover the sister group relationship between Wuttagoonaspis (Australia) and Yiminaspis (China) proposed by Dupret (2008), the resemblances residing mainly in primitive arthrodire skull characters (discussed further in the next section).…”

“…3 Various placoderms from East Gondwana (a-g) compared with one from South China (h). a and b Wuttagoonaspis milligani skull (a) and reconstruction (b) as described by Young and Goujet (2003) from the Georgina Basin; c-e Phyllolepid placoderms: Placolepis dorsal reconstruction (c, after Long 1993), isolated phyllolepid bones from Victoria (d) and Antarctica (e), all showing characteristic sinuous ridged ornament; f Skull reconstruction of Toombalepis tuberculata described by Young and Goujet (2003); g Holotype skull of Edgellaspis gorteri described by Hunt and Young (2011) from the Hatchery Creek Group at Wee Jasper (locality 5, Fig. 1).…”

Depositional environment, stratigraphy, structure and paleobiology of the Hatchery Creek Group (Early–?Middle Devonian) near Wee Jasper, New South Wales

“…In China, the earliest Bothriolepis occurrence is also now revised to Emsian (Zhu 2000), and close similarities have been noted between the Hatchery Creek osteolepid material and Chinese forms including Kenichthys (Chang & Zhu 1993;Chang & Yu 1997), which also comes from the Emsian (Zhu 2000). Of new additions to the fish fauna, the enigmatic placoderm Edgellaspis compares with various placoderms from the Early Devonian of China (Hunt & Young 2011). A possible second species of the asterolepid antiarch Sherbonaspis has a median dorsal spine like the well-known Byssacanthus from the Givetian of the Northern Hemisphere (Karataj ut _ e-Talimaa 1960).…”