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Fossils from Monmouth County, New Jersey

Sawfish (Ischyrhiza cf. avonicola)

Age – Late Cretaceous; Commonality – Scarce (?); Size – Rostrals: ¼-½ inch, Oral teeth: likely smaller than that of I. mira

This Sawfish is a bit ambiguous. Its rostrals may actually be the posterior rostrals of I. mira; however, there are a couple differences which I have noted: the roots seem to curve in a distinct fashion, the two carinae are perpendicular in comparison to the carinae of I. mira, and the crowns do not curve that much distally (I. mira posterior rostrals are curved pretty significantly). The oral teeth of this Sawfish cannot be distinguished from that of I. mira if in fact they are different species.

Rostral Spines

Ventral View

Dorsal View

Sawfish (Ischyrhiza avonicola) Rostral spine, Cretaceous, New Jerse

Anterior View

Posterior View

Basal View

Occlusal View

A nice rostral. Note the twist in the root, the exaggerated root ridges, and the disproportionally small crown. EDIT – this is actually an I. mira posterior rostral.

Dorsal View

Ventral View

Anterior View

Posterior View

Basal View

Occlusal View

This one is the typical “type” found. It looks quite a bit different and has the usual wear.

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