] lizard") is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of large ichthyosaur

Ichthyosaur

Ichthyosaurs were giant marine reptiles that resembled fish and dolphins...

 (a marine reptile, not a dinosaur) that lived during the middle Triassic

Middle Triassic

In the geologic timescale, the Middle Triassic is the second of three epochs of the Triassic period or the middle of three series in which the Triassic system is divided. It spans the time between 245 ± 1.5 Ma and 228 ± 2 Ma...

 period, approximately 235 million years ago. This marine reptile came from the family Shastasauridae and was named by Dal Sasso and Pinna in 1996. The type of species is Besanosaurus leptorhynchus meaning "long-beaked reptile from Besano

Besano

Besano is a town and comune located in the province of Varese, in the Lombardy region of northern Italy....

."

Description

Besanosaurus was a marine reptile nearly 6 meters in length and had a similar shape to dolphin

Dolphin

Dolphins are marine mammals that are closely related to whales and porpoises. There are almost forty species of dolphin in 17 genera. They vary in size from and , up to and . They are found worldwide, mostly in the shallower seas of the continental shelves, and are carnivores, mostly eating...

s. It had a thin snout, fairly small teeth, no dorsal fin, and a long and straight tail. It was an eel-like swimmer with moderate speed along with rapid acceleration and good maneuvering, and lived in tropical seas, in coastal, and Caribbean

Caribbean

The Caribbean is a crescent-shaped group of islands more than 2,000 miles long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north...

-like environments. Besanosaurs were carnivorous and fed mainly on small fish, cephalopods, and marine reptiles.. The reptile's reproduction was ovoviviparous, meaning the eggs incubated inside the body and hatched at birth.

Discovery

The bones of Besanosaurus were first discovered in "Sasso Caldo" quarry in the spring of 1993 by the volunteers of the paleontological group of Besano

Besano

Besano is a town and comune located in the province of Varese, in the Lombardy region of northern Italy....

, a small town in the Lombardy

Lombardy

Lombardy is one of the 20 regions of Italy. The capital is Milan. One-sixth of Italy's population lives in Lombardy and about one fifth of Italy's GDP is produced in this region, making it the most populous and richest region in the country and one of the richest in the whole of Europe...

 region of north Italy

Italy

Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

. The fossil was almost completely embedded in the rock and could be first seen only through x-rays; to detect the content of the 38 slabs of stone enclosing the skeleton, 145 radiographs were necessary. The skeleton of Besanosaurus came to light in the paleontological laboratory of Museo Civico di Storia Naturale di Milano after 16500 hours of preparation. The preparators removed the rock enclosing the fossil step by step, working under a stereo microscope

Stereo microscope

The stereo or dissecting microscope is an optical microscope variant designed for low magnification observation or a sample using incident light illumination rather than transillumination. It uses two separate optical paths with two objectives and two eyepieces to provide slightly different viewing...

with chisels, needles and pins. The 38 slabs were reassembled and a silicon rubber matrix was made, from which a cast of the original specimen was obtained.

External links

• Besanosaurus at Gigadino