Distribution Geographic
widespread in the Early Miocene being found in Tasmania at Cape Grim, and Fossil Bluff, in both the Freestone Cove and Fossil Bluff Sandstones, and in Victoria, from 64-66 m in Mallee Bore No. 8, and from the Fyansford Formation at Curlcwis (Kemp, 1991) [1275]

Description
Original description after CHAPMAN & PRITCHARD, 1904 [446]: Cestracion cainozoicus, sp. nov. (PI. XI., Figs. 5-8. PL XII., Fig. 2). Various lateral teeth showing variation comparable with that of the crushing teeth of the recent C. philippi. In shape the specimens vary from almost semicircular through subrhomboidal to elongate-oblong ; the latter form usually showing a stronger incurvation of the outer lateral edge. In the best preserved specimens the surface towards the outer lateral edges shows the submedian ridge as a fine elevated band from which proceed anastomosing ridges giving rise to the pitted appearance at the extremities of the teeth. The arrangement of the ridges running off the submedian ridge is generally parallel and at right angles to it. As in common with other Cestraciont teeth, the base of the outer concave side is usually excavate, giving rise to an articulating ridge at the junction of the crown with the root. The surface of the crown is, generally speaking, strongly convex, and is apparently much smoother than that of the living species. An interesting point of agreement, however, is shown in one specimen which has flaked off superficially from the rest of the crown, a feature which may be readily tested in the living species.
Dimensions.—Specimen (a) (semicircular form)—Length, 13 mm.; breadth, 7 mm.; height, 5 mm. Specimen(b) (subrhomboidal form)—Length, 18.5mm.; breadth, 11 mm.; height, 7 mm. Specimen (c) (elongate oblong form)—Length, 18 mm.; breadth, 7 mm. ; height, 5 mm. Specimen (d)—Length, 26 mm.; breadth, 10 mm. ; heiglit, 7 mm.
Locality and Horizon.—From the nodule band at the base of the cliffs, Beaumaris, Port Phillip. National Museum Collection, collected by the late Mr. W. Kershaw, and the late Mr. W. B. Jennings ; also in the private collections of Messrs. Dixon and G. B. Prit chard.
From the nodule band at the base of the upper beds Grange Burn, near Hamilton, Western. Victoria. Nat. Mus. Coll., presented by Messrs. F. Spry and A. A. Kelley, also Coll. G. B. Pritchard.
The majority of the specimens hitherto obtained of this species have been from the Kalimnan Beds, but as many show considerable erosion it is probable that they may have been derived from the Balcombian. Cixrlewis; Beds, near Geelong (Nat. Mus. Collection, presented by A. C. Curlewis); Murgheboluc (T. S. Hall Coll.)—Balcombian. Warranooke, 23 miles north of Stawell (Nat. Mus. Collection from Mines Department, 3502).—Banvonian. Observations.—The genus itself has been previously recorded from our Tertiaries by Tate (25, p. 246), and by Hall and Pritchard (12, p. 304), but no described Australasian Tertiary species has hitherto been known. For confirmatory evidence of the generic affinities of our specimens thin slices of the teeth have been microscopically examined, and they show the irregular habit of the pulp-canals and the characteristic outspread canaliouli near the upper surface, a feature which we have also seen in actual recent specimens, and which has also been well illustrated by Owen in his Odontography (22). The first European Tertiary record of Cestracion was made by Winkler (27, p. 17) from the Bruxellian (Middle Eocene) of Belgium, and subsequently by A. S. Woodward (32, pp. 6, 7, 13) from the London Clay (Lower Eocene).

Remarks
shark-references Species-ID=2751;

References