AMMONITES OF MOZAMBIQUE

Natural History Museum of Lisbon, Photo Luis Lima

GAVIALOSUCHUS CROCODILE OF CHELAS

This well-preserved Miocene fossil crocodile is Gavialosuchus americanus lusitanicus, (Sellards, 1915) who lived in the area near Chelas, a locality near the airport in Lisbon, Portugal around 12 million years ago. When he was alive, that area of the world was flooded and home to Mastodons and other ancient animals.

This fellow was quite the beast. The complete crocodile would have been 8-9 meters in length. Crocodiles are reptiles, which means that they are cold-blooded, are covered in dry, scaly skin, and have a backbone. They are sometimes called ‘living fossils’ because they have been living on Earth since the time of the dinosaurs.

Although they have been around for millions of years, their bodies have not changed very much during that time because they are such successful predators. Unlike alligators, crocodiles have very pointed snouts, and their upper and lower jaws are the same size. Crocodiles have webbed feet, which makes them fast swimmers.

Their bodies are very streamlined, meaning they can slide quickly through the water to catch their prey. Their size depends on the crocodile species with some modern species growing to over 7 meters (23 feet) long and weighing about 1,000 kilograms or 2,200 pounds. This ancient specimen is now housed in the Geological Museum of Lisbon. He would have been bigger than his modern cousins and a formidable predator. Luis Lima recently had the pleasure of visiting their collections and shared this photo. The museum was built in 1857 and is home to beautiful paleontology, archaeology and mineral specimens. Should you find yourself in Lisbon, it is well worth a trip.

MOZAMBIQUE AMMONITE

Natural History Museum of Lisbon. Photo: Luis Lima

AMMONITE OF THE RHÔNE

An exquisite specimen of the delicately ridged ammonite, Porpoceras verticosum, from Middle Toarcian outcrops adjacent the Rhône in southeastern France.

Porpoceras (Buchman, 1911) is a genus of ammonite that lived during the early and middle Toarcian stage of the Early Jurassic. We see members of this genus from the uppermost part of Serpentinum Zone to Variabilis Subzone. These beauties are found in Europe, Asia, North America and South America.

Ammonites belonging to this genus have evolute shells, with compressed to depressed whorl section. Flanks were slightly convex and venter has been low. The whorl section is sub-rectangular. The rib is pronounced and somewhat fibulate on inner whorls (just wee nodes here) and tuberculate to spined on the ventrolateral shoulder. It differs from Peronoceras by not having a compressed whorl section and regular nodes or fibulation. Catacoeloceras is also similar, but it has regular ventrolateral tubercules and is missing the classic nodes or fibulation of his cousins.

This specimen hails from southern France near the Rhône, one of the major rivers of Europe. It has twice the average water level of the Loire and is fed by the Rhône Glacier in the Swiss Alps at the far eastern end of the Swiss canton of Valais then passes through Lake Geneva before running through southeastern France. This 10 cm specimen was prepared by the supremely talented José Juárez Ruiz