Monday, 29 October 2018

PHYLLOCERAS CONSANGUINEUM

Phylloceras consanguineum (Gemmellaro 1876) a fast-moving carnivorous ammonite from Late Jurassic (Middle Oxfordian) deposits near Sokoja, Madagasgar, off the southeast coast of Africa. (22.8° S, 44.4° E: 28.5° S, 18.2° E)

This classical Tethyan Mediterranean specimen is very well preserved, showing much of his delicate suturing in intricate detail. Phylloceras were primitive ammonites with involute, laterally flattened shells.

They were smooth, with very little ornamentation, which led researchers to think of them resembling plant leaves and gave rise to their name, which means "leaf-horn."

They can be found in three regions that I know of.  In the Jurassic of Italy near western Sicily's Rosso Ammonitico Formation, Lower Kimmeridgian fossiliferous beds of Monte Inici East and Castello Inici (38.0° N, 12.9° E: 26.7° N, 15.4° E) and in the Arimine area, southeastern Toyama Prefecture, northern central Japan, roughly (36.5° N, 137.5° E: 43.6° N, 140.6° E) Dōitashimashite ; )

Saturday, 27 October 2018

RHACOLEPIS BUCCALIS

Rhacolepis Buccalis, an extinct genus of ray-finned fossil fish in carbonate concretion, Lower Cretaceous, Santana Formation, Brazil. These nektonic carnivores swam our ancient seas 122-109 million years ago.

Le premier et unique géoparc mondial UNESCO est situé dans le Cariri du Ceará (géoparc Araripe), dans l'intérieur semi-aride de la région Nordeste, Brésil

Thursday, 25 October 2018

BREWERICERAS HULENENSE

Brewericeras hulenense (Anderson 1938) a fast-moving, nektonic (no idle floating here!) carnivorous ammonite from the Lower Cretaceous (Albian) of Haida Gwaii (aka Queen Charlotte Islands), British Columbia, Canada.

Ammonites belong to the class of animals called mollusks. More specifically they are cephalopods. and first appeared in the lower Devonian Period.

Cephalopods were an abundant and diverse group during the Paleozoic Era. This specimen is just over 12cm in length, a little under the average of 13.4cm. There are several localities in the Queen Charlotte Islands where Brewericeras can be found (six that I know of and likely plenty more!) This specimen was found on a trip a few years back done with the Vancouver Paleontological Society and a few of the members of some of the Island paleo groups. The preservation is quite remarkable!

Brewericeras are also found in Albian deposits in Svedenborgfjellet, Ulladalen, Norway (Cretaceous of Svalbard and Jan Mayen - så fin!) (77.7° N, 15.2° E: paleocoordinates 66.6° N, 13.6° E) and Matanuska-Susitna County, Alaska, 62.0° N, 147.7° W: paleocoordinates 57.3° N, 85.6° W (112.6 to 109.0 Ma.)

Tuesday, 23 October 2018

Friday, 12 October 2018

Tuesday, 9 October 2018

CALYCOCERAS TARRANTENSE

Previously Calycoceras Tarrantense, this ammonite is now called Conlinoceras tarrantense after J.P. Conlin, a famous early 20th century Texas fossil collector.

Ammonite expert Bill Cobban used this collection to describe many Texas Cretaceous ammonites species including this species from Tarrant County, Arlington, Texas.

He was a surveyor by training and kept incredibly detailed notes on the context of his fossils.

Conlin donated his collection to the USGS and we’ve learned much by studying it along with other specimens from the Lone Star State. Almost a quarter of Texas is covered by Cretaceous strata, much of it fossiliferous. If we stepped back 95 million years, the world and what we now call Texas, was a very different place.

95 million years ago, during the late Cretaceous, a shallow seaway separated North America into separate eastern and western landmasses. We have a pretty complete picture in the fossil record of the western groups of species but relatively little in comparison for their cohorts in the east.

At the time this fellow was swimming our ancient seas, he was sharing the Earth with carnivorous dinosaurs, duck-billed dinosaurs, mammals, crocodilians, turtles, a variety of amphibians, prehistoric bony fish, oddly prolific sea cucumbers, various invertebrates and plants. Many of these sites are just being written up now and contain new species just being discovered.

During the Late Cretaceous Period a shallow seaway separated North America into separate eastern and western landmasses. The Woodbine Formation in Texas preserves a rare fossil record of this time for the east, but many of these fossils are isolated and incomplete, making interpretations more difficult. Preliminary excavations at the AAS are providing hints at a more complete ecosystem, preserving similar patterns of change to what we see in the west.

The AAS contains an extraordinary diversity, abundance, and quality of fossil material, preserving one of the most complete terrestrial ecosystems known for this time period and area.

The AAS has a lot to tell us about Late Cretaceous life in the east. Over 2200 individual specimens have been found belonging to numerous groups including carnivorous dinosaurs, duck-billed dinosaurs, crocodilians, turtles, mammals, amphibians, sharks, bony fish, invertebrates, and plants.

Many of the fossils found here represent brand new species and studying these fossils will help to establish the geographic and environmental forces that shaped Cretaceous ecosystems in North America by providing a necessary comparison to the fossil record of the west.