Cowralepis mclachlani Ritchie, 2005

Taxonomy

Phyllolepid Placoderm

Kingdom: Animalia
Phylum: Chordata
Class: PLACODERMI McCoy, 1848
Order: PHYLLOLEPIDA Stensio, 1934
Family: PHYLLOLEPIDIDAE Woodward 1891
Genus: Cowralepis
Species: Cowralepis mclachlani
Author Citation Ritchie, 2005

Geological Time Scale

Eon: Phanerozoic
Era: Paleozoic
Period: Devonian
Sub Period: None
Epoch: Middle
International Age: Givetian (late)

Stratigraphy

Rocky Ponds Group
Dulladery Volcanics Formation
Merriganowry Shale Member

Provenance

Acquired by: Purchase/Trade

Dimensions

Length: 20 cm

Location

Quarry near Merriganowry Bridge
Cowra
New South Wales
Australia

• australia
• cowra
• cowralepis
• devonian
• phyllolepid
• placoderm
• tff-oilshale-ch448

Comments

Taxonomy from Ritchie 2005.

Diagnosis fro Ritchie 2005, p. 222: "Moderately large phyllolepid, reaching ca. 35 cm in length. Widest part of nuchal plate lies just posterior to centre of ossification; anterior nuchal margin more angular than in Placolepis, less angular than in Austrophyllolepis and Phyllolepis. Nuchal plate same length as or longer than median dorsal plate in juveniles; nuchal plate 20-60% longer than median dorsal plate in adults. Supraorbital canal, infraorbital canal nd pit-line grooves not developed on nuchal plate. Lateral line canal groove on paranuchal pate diverges anteriorly from nuchal margin and canal groove crosses anterolateral margin between 78-92% PNu length. Marginal plate separates postorbital and paranuchal plates. Marginal plate and posterior division of postorbital plate lack contact with the nuchal plate in juveniles, leaving fenestra between them; marginal plate and posterior division of postorbital plate meet lateral margin of nuchal in adults, fenestra reduced. Posterior dorsolateral plate present; small, subtriangular, hidden under lateral margin of median dorsal plate; posterior lateral plate absent. Anterior and posterior median ventral plates both present. Occipital region of endocranium ossified; vertebral column fused anteriorly, forming long narrow synarcual under median dorsal plate."

Line drawing from Ritcie 2005, p. 222:

References:

Ritchie, A. (2005): Cowralepis, a new genus of phyllolepid fish (Pisces, Placodermi) from the late middle Devonian of New South Wales, Australia. Proceedings- Linnean Society of New South Wales 126:215-259 · March 2005.
Carr, RK, Johanson, Z., Ritchie, A. (2009) The phyllolepid placoderm Cowralepis mclachlani: insights into the evolution of feeding mechanisms in jawed vertebrates. J. Morphol., 2009 Jul;270(7):775-804. doi: 10.1002/jmor.10719.