Austroptyctodus

Austroptyctodus Temporal range: Late Frasnian
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	†Placodermi
Order:	†Ptyctodontida
Family:	†Ptyctodontidae
Genus:	†Austroptyctodus Long, 1997
Species:	†A. gardineri
Binomial name
†Austroptyctodus gardineri Long, 1997
Synonyms
Ctenurella gardineri

Austroptyctodus gardineri is a small ptyctodontid placoderm fish from the Upper Devonian Gogo Formation of Western Australia. First described by Miles & Young (1977)^[1] as a new species of the German genus Ctenurella. Long (1997)^[2] redescribed the German material and found major differences in the skull roof pattern so assigned it to a new genus, Austroptyctodus. This genus lacks spinal plates and has Ptyctodus-like toothplates.

The most significant discovery about Austroptyctodus is that one specimen depicts a female pregnant with 3 unborn embryos inside her, showing that like Materpiscis, also from Gogo, this genus was a live bearer that reproduced through internal fertilization.^[3]

Feeding habits

Austroptyctodus fossil individuals have ostracods recovered in the abdominal region. These ostracods were related to nocturnal ones, suggesting it hunted at night.^[4]

References

^ Miles, R.S. & Young, G.C. 1977. Placoderm interrelationships reconsidered in the light of new ptyctodontids from Gogo Western Australia. Linn. Soc. Symp. Series 4: 123-198.
^ Long, J.A. 1997. Ptyctodontid fishes from the Late Devonian Gogo Formation, Western Australia, with a revision of the German genus Ctenurella Orvig 1960. Geodiversitas 19: 515-555.
^ Long, J.A., Trinajstic, K.,Young, G.C. & Senden, T. 2008. Live birth in the Devonian period. Nature 453: 650-653.
^ https://www.lyellcollection.org/doi/full/10.1144/jgs2021-105

"Placodermi"

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata

Gnathostomata

see Gnathostomata
Placodermi	see below↓

Placodermi

Acanthothoraci *

Hagiangella
Palaeacanthaspidae*	Arabosteus Dobrowlania Kimaspis Kolymaspis Kosoraspis Palaeacanthaspis Radotina Romundina Sudaspis Tlamaspis
Weejasperaspididae	Murrindalaspis Weejasperaspis

Petalichthyida

Diandongpetalichthys Neopetalichthys
Quasipetalichthyidae	Eurycaraspis Pauropetalichthys Quasipetalichthys
Macropetalichthyidae	Ellopetalichthys Epipetalichthys Lunaspis Macropetalichthys Notopetalichthys Shearsbyaspis Tongdzuylepis Wijdeaspis