FOSSIL FAUNA OF HAIDA GWAII

This lovely slate grey and beige ammonite with the fine ribbing is Brewericeras hulenense (Anderson 1938) — a fast-moving, nektonic (no idle floating here!) carnivorous ammonite from the Lower Cretaceous (Albian) of Haida Gwaii, British Columbia, Canada.

This specimen is just over 12cm in length, a little under the average of 13.4cm. There are several localities in the islands of Haida Gwaii where Brewericeras can be found — six that I know of and likely plenty more.

The islands of Haida Gwaii lay at the western edge of the continental shelf due west of the central coast of British Columbia. 

They form Wrangellia, an exotic tectonostratigraphic terrane that includes Vancouver Island, parts of western British Columbia and Alaska.

It is always interesting to see who was making a living and co-existing in our ancient oceans at the time these fossils were laid down. 

We find multiple beautifully preserved specimens of the spiny ammonite, Douvelleiceras spiniferum along with Brewericeras hulenense (shown here), Cleoniceras perezianum and many cycads in concretion.

The Lower Jurassic ammonite faunas found at Haida Gwaii are very similar to those found in the Eastern Pacific around South America and in the Mediterranean. 

The strata exposed at Maple Island, Haida Gwaii are stratigraphically higher than the majority of Albian localities in Skidegate Inlet. The macrofossil fauna belonged to the Upper part of the Sandstone Member of the Haida formation.

The western end of the island contains numerous well-preserved inoceramids such as Birostrina concentrica and a few rare ammonites of Desmoceras bearskinese. 

The eastern shores are home to unusual ammonite fauna in the finer-grained sandstones. Here we find the fossils as extremely hard concretions while others were loose in the shale. Species include Anagaudryceras sacya and Tetragonites subtimotheanus. A large whorl section of the rare Ammonoceratites crenucostatus has also been found here.