''Neeyambaspis enigmatica'' ("Enigmatic shield of Neeyamba Hill") is the lesser known of the two species of pituriaspid

agnatha Agnatha (, Ancient Greek 'without jaws') is an infraphylum of jawless fish in the phylum Chordata, subphylum Vertebrata, consisting of both present (cyclostomes) and extinct ( conodonts and ostracoderms) species. Among recent animals, cyclosto ...

ns. The species lived in estuaries during the Middle

Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...

, in what is now the

Georgina Basin The Georgina Basin is a large (c. 330,000 km2) intracratonic sedimentary basin in central and northern Australia, lying mostly within the Northern Territory and partly within Queensland.Smith, KG (1972). "Stratigraphy of the Georgina Basin. ...

of Western

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_ ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. ''N. enigmatica'' differed from its relative, ''

Pituriaspis doylei ''Pituriaspis doylei'' is one of two known species of jawless fish belonging to the Class Pituriaspida, and is the better known of the two. The species lived in estuaries during the Givetian epoch of the Middle Devonian, 390 million years ago in ...

'', in that the headshield was triangular, rather than elongated, that the rostrum was much smaller and shorter, and that there was no cavity at the base of the rostrum that suggested the presence of nasal openings.

References

* Janvier, Philippe. ''Early Vertebrates'' Oxford, New York: Oxford University Press, 1998. * Long, John A. ''The Rise of Fishes: 500 Million Years of Evolution'' Baltimore: The Johns Hopkins University Press, 1996. Pituriaspida Prehistoric jawless fish genera Fossil taxa described in 1991 {{Devonian-jawless-fish-stub