Friday, 23 August 2019

GREEN RIVER HETEROPTERAN

A delightful Heteropteran collected this past week by Jim Barkley from Eocene exposures of the Green River Formation of Western Colorado, which was once the bottom of an extensive series of Eocene lakes.

The Green River Formation is particularly abundant in beautifully preserved fossil fish, eleven species of reptiles including a 13.5ft crocodile, an armadillo-like mammal, Brachianodon westorum, bats, birds and other freshwater aquatic goodies.

Thursday, 22 August 2019

CARNOTAURUS OF ARGENTINA

Carnotaurus sastrei, a genus of large theropod dinosaur that roamed, Argentina, South America during the Late Cretaceous period, 72 to 69.9 million years ago.

This fellow (or at least his skull) is on display at the Natural History Museum in Madrid, Spain. For now, he is the only known genus of this species of bipedal predator.

The skull is quite unusual. Initially, it has a very marine reptile feel (but make no mistake this guy is clearly a terrestrial theropod). Once you look closer you see his bull-like horns (from whence he gets his name) that imply battle between rivals for the best meal, sexual partner and to be the one who leads the herd.

Wednesday, 21 August 2019

RIOMAGGIORE: SUNSETS AND SQUID INK

Riomaggiore or 'Rimazuu' in the local Ligurian language, is a lovely seaside village that can trace its roots to the good taste of Monks who settled here in the early thirteenth century.

Here, great wine is produced and consumed along with a huge variety of seafood, figs, olives, capers and Limoncello in the wee restaurants and bars along the Via Colombo that look out onto the Gulf of Genoa. Inspired by the praise of Dante, Petrarch and Boccaccio, I had the great pleasure to venture there years ago, prior to the huge slides that plagued the Cinque Terre. I ate one of my finest meals, a pasta made from squid ink, one evening I was there. Drawn to the picturesque beauty of the Liguria region, ancient vineyards and the irresistible "photo a moment" scenery, we travelled from village-to-village, all along the Cinque Terre.

Liguria remains one of the wildest parts of the Ligurian littoral east of Genoa. The coastline is home to incredibly complex and exciting geology. It is composed of the Maritime Alps in the west and the Ligurian "nappies," continental margin ophiolites, of the Apennines in the east.

Along the coast, the north-northwest convergence of the Alpine orogeny gives way to the active east-northeast convergence along the Apennines. All of this tasty geology can be observed while walking from town to town from Riomaggiore through Manarola, Corniglia and Vernazza. We stayed in Monterosso al Mare during our visit, meeting up with friends and then visiting them in their home city of Milan. If one is lucky enough to be invited as a guest, the geology of the Via dell Amore is true to its namesake and well worth the trip.

Monday, 19 August 2019

CERATITES AMMONITE WITH BEAK

A lovely example of the ammonite, Cératites Nodosus, an extinct genus of nektonic marine carnivore from shell limestone superior deposits near Alsace on the Rhine River plain of northeastern France.

You can see the nice ceratitic suture pattern on this specimen with his smooth lobes and frilly saddles. The sutures would have increased the strength of the shell and allowed Ceratites (de Haan, 1825) to dive deeper, bearing the additional pressure of the sea in search of food.

Ammonite shells are made up predominantly of calcium carbonate in the form of aragonite and proteinaceous organic matrix or conchiolin arranged in layers: a thin outer prismatic layer, a nacreous layer and an inner lining of prismatic habitat. While their outer shells are generally aragonite, aptychus are distinct as they are composed of calcite.

The aptychus we see here, hard anatomical structures or curved shelly plates now understood to be part of the body of an ammonite, are often referred to as beaks. If you look closely at this specimen, you can see the beak of the ammonite, that wee pointed piece, near the centre.

These ammonites lived in open shallow, to subtidal and basinal environments some 247 to 221 million years ago. We've found them, thus far, in just over forty collections from nearly ninety fossil deposits around the globe. Fossils of species have been found in the Triassic of Austria, Canada, China, France, Germany, Hungary, India, Israel, Italy, Pakistan, Poland, Russia, Thailand, Turkey and the United States.

The parent taxon is Ceratitinae according to E. T. Tozer 1981. That's our own Tim Tozer, one of the great knights-errant of the Triassic timescale. It was Tim Tozer and Norm Silberling who published the classic milestones of the Triassic timescale, "Biostratigraphic Classification of the Marine Triassic in North America, Geological Society of America, Special Paper 110." The Global Triassic: Bulletin 41 from the New Mexico Museum of Natural History and Science by Lucas and Spielmann honours them in their work. Collection of Ange Mirabet, Strasbourg, France.