Saturday, December 6, 2014

Sorry for the hiatus - GSNZ conference and field trip to Waihi/Ohawe beaches, Taranaki

Hey all, as promised, I've only had a minimal amount of time to contribute to blogging this fall, owing to more pressing concerns (such as my thesis, which I have about two months left to complete). It's been one week since I've been back from the Geoscience Society of NZ annual conference, where I presented on my dissertation research on Oligocene eomysticetids from the south island of NZ, specifically on feeding strategy of the earliest toothless mysticetes. I actually won 1st runner up for best student oral presentation, and labmate Yoshi Tanaka received the award for best poster presentation for his poster on Oligocene platanistoid dolphins from the same localities. Otago students did exceedingly well, sweeping 5 out of 6 best presentation awards, all with the exception of top oral presentation. To be fair, Otago students made up almost half of all students attending the conference, but then again we received more than half the awards. All this highlights Otago as one of the best places to study geology in NZ.

Not all of the days were paleontology themed (in fact, only one was) so some plans were made to go out into the field. I have long wanted to visit some fossil sites in South Taranaki, which have recently been getting some attention on places like The Fossil Forum thanks to a series of remarkable discoveries by some private collectors on the North Island. I flew up to Wellington the day before the conference started, rented a car with labmate Josh Corrie, and swung by Waihi Beach.

Fossil invertebrates are abundant in the cliffs, and require little more than a knife or a few casual taps from a rock hammer to be pried loose from the rather soft siltstone. Large scallops, beautifully preserved oysters, and spectacular gastropods are in abundance. Occasional barnacles are present, and bryozoans are rare; I found a single, beautifully preserved bryozoan colony that I handed to Alan Tennyson for Te Papa (National Museum of New Zealand) fossil collections. In concretions, much larger oysters and scallops can be found, but are substantially more difficult to prepare.

Fossil vertebrates include seals (known from isolated braincases, mandibles, humeri, innominates, femora, other postcrania, and partial associated skeletons), dolphins (known from several skulls, mandibles, a single periotic, and vertebrae), rare baleen whales (mostly ribs, although a partial skull and skeleton of a new species of Balaenoptera are in collections at Te Papa), and marine birds including shearwaters, giant petrels, albatrosses, a spheniscid penguin, and a pelagornithid bird (skulls, jaws, partial skeletons). Bony fish and sharks are also known - I saw vertebrae from lamniform sharks including a candidate for Carcharodon carcharias, and toothplates of the elephant fish Callorhynchus (a chimaera) and a single associated set of mandibular/palatoquadrate cartilages with teeth of the angel shark Squatina also exist in private collections. Vertebrates are almost always in small concretions, and are cracked open with large sledgehammers.

The view to the west from Waihi stream.

A large scallop exposed in the Ohawe Siltstone.

Further up the beach, here's the view towards Ohawe Beach off in the distance.

Large gastropods make for a nice prize.

Fordyce student Josh Corrie looks for concretions at Waihi Beach. Right around this spot, a pelagornithid jaw (seen below) was collected less than two months ago.

Nearby is Mt. Taranaki, an enormous stratovolcano; we had staggering views of the mountain from New Plymouth. Mt. Taranaki was used as a stand-in for Mt. Fuji in the film "The Last Samurai".

Te Papa paleontology curator Alan Tennyson looking for concretions at Waihi Beach.

Otago BSc honors student Alexis Belton helping in the search for concretions. I offered Alexis a lift back to Wellington in exchange for a few bucks for gas and helping us find fossils.

 Alan cracks open a concretion.

Many of the concretions are even in the water still; here's a cluster of several good candidates. None had anything inside them, of course, but this is what to look for. Anything looking silty, spherical, and like a bowling ball (or smaller) without large shells.

We actually ended up breaking one of Alan's two sledge hammers; the haft was a bit old and perhaps somewhat rotten near the head.

Another beautiful gastropod.

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