Tuesday 29 July 2014

Sunday 27 July 2014

Tuesday 22 July 2014

AMMONITES & MARINE REPTILES FROM THE MYSTERIOUS CREEK FORMATION

The Cretaceous-Jurassic exposures near Harrison Lake, British Columbia are an easy two hour drive from Vancouver and another hour or so to our final destination, the unyielding siltstone of the Callovian, 166 million year old, Mysterious Creek Formation.

A few hours of collecting yield multiple bivalves, ammonites, including what looks to be two new species. 

Amongst the best specimens of the day are several small, fairly well preserved Cadoceras (Paracadoceras) tonniense, a few Cadoceras (Pseudocadoceras) grewingki and two relatively complete specimens of the larger, smooth Cadoceras comma. Further up the road, we photograph blocks of buchia and large boulders encrusted with perfectly preserved belemnites from ancient squid.

Interestingly, the ammonites from here are quite similar to the ones found within the lower part of the Chinitna Formation, Alaska and Jurassic Point, Kyuquot, on the west coast of Vancouver Island. The siltstone here at Harrison has also offered up a small section of vertebra from a poorly preserved marine reptile, a find I'm rather keen to make one day. So, after much hammer swinging, I've enjoyed a splendid day, collected beautiful specimens and feel a wee bit closer to the big find. 

Sunday 13 July 2014

TYLOSTOMA TUMIDUM

This lovely big fellow is Tylostoma tumidum, an epifaunal grazing Lower Cretaceous Gastropod from white, micritic, coarsely nodular limestone deposits of the Goodland Formation at White Settlement west of Fort Worth, Texas, USA. (171.6 to 58.7 Ma). The bedding here is massive with some thin clay beds. The macro fossil found here include the ammonite, Oxytropidoceras acutocarinatum, pelecypods such as Protocardia, Pinna and Lima wacoensis along with heart-shaped urchins in abundance and lovely gastropods such as this beauty, Tylostoma tumidum.

Tylostoma have thick, smooth shells with a moderately elevated spire. Their aperture is ovato-lunate with the lips meeting above at a sharp angle. The outer lip is furnished internally, running the whole length and ending with a thickened edge. This specimen shows the wear and tear of erosion common at the site.

Saturday 5 July 2014

LIVING FOSSIL: COMB JELLY

Living Fossil / Comb Jelly / Ctenophore
This lovely invertebrate is a Comb Jelly, a living fossil. Coined by Charles Darwin, the term “living fossils” is used to describe organisms that have remained largely unchanged for millions of years. While simple in design, the Comb Jellies have stood the test of time. The color you see here is light refracting on rows of Mertensia ovum.