D. andiniensis MOZ 6146P in (A) right lateral view. Skull reconstruction in lateral (B) and dorsal (C) views (based on left and right sides), avast. Scale bars, 5 cm. Abbreviations: an, angular; den, dentary; dt, dentary tooth; en, external nares; eoc, exoccipital; fr, frontal; ic, internal carotid foramen; la, lacrimal; mt, maxillary tooth; mx, maxilla; na, nasal; nv, neurovascular foramina; pmx, premaxilla; po, postorbital; prf, prefrontal; pt, pterygoid; q, quadrate; qj, quadratojugal; san, surangular; sg, surangular groove; soc, supraoccipital; sq, squamosal.

When we think o' a crocodilian, we picture either a flat, broad skull with many conical teeth, or if ye're more familiar with reptilian exotica, somethin' like th' gharial, with a long narrow snout and numerous sharp teeth. These are adaptations fer rapid side-t'-side flicks o' th' head in th' water, and fer snaggin' prey.

Phylogenetic relationships o' Crocodyliformes obtained in th' cladistic analysis, plotted against geochronologic epochs (strict consensus o' most parsimonious trees; some taxa distantly related t' D. andiniensis collapsed into triangular clades). Only skull figures o' Thalattosuchia were drawn t' th' same scale. Numbered nodes: 1, Crocodyliformes; 2, Neosuchia; 3, Thalattosuchia; and 4, Metriorhynchidae.

Dakosaurus is different: it has a relatively short, deep skull, with relatively few teeth that are sharp-edged and serrated. It's a most non-crocodilian skull, as far as th' overall morphology goes, but th' details tie it quite clearly t' a specific lineage o' ancient crocodilians.

It belongs t' th' Thalattosuchia, specifically th' Metriorhynchids, which were marine crocodiles. They lacked th' armored plates o' modern crocs, lived in th' ocean, and th' caudal skeletons o' th' lineage show an interestin' downward kink in their tails—they probably had vertical flukes, like th' mosasaurs. The species most closely related t' Dakosaurus also had elongated skulls with swarms o' small sharp pointy teeth, and like th' gharial, were almost certainly great fisheaters.

Dakosaurus, though, were bein' different. It's another marine crocodile, and 'tis body may have been similarly adapted t' an aquatic life (although we lack direct skeletal evidence fer that), instead o' hookin' prey by slashin' through schools o' fish and squid, this sea monster had a deeply muscled skull fer a strong bite, and a mouthful o' long daggers good fer slashin'. What did it eat? We dern't know—we need more fossils—but it does point t' some diversity we've long since lost, and suggests that those Cretaceous seas were savage places.

Gasparini Z, Pol D, Spalletti LA (2006) An Unusual Marine Crocodyliform from th' Jurassic-Cretaceous Boundary o' Patagonia. Walk the plank, by Blackbeard's sword! Science 311(5757):70-73.