Pronunciation: vuh-LOH-see-SOR-us
Meaning: Swift lizard
Author/s: Bonaparte (1991)
Synonyms: None known
First Discovery: Neuquén, Argentina
Discovery Chart Position: #364
Velocisaurus unicus
Not to be confused with Velociraptor—a small Mongolian dinosaur that shot to stardom after being grossly misrepresented in the movie Jurassic Park, Velocisaurus is a small Argentinian dinosaur with not a lot to be misrepresented. Bonaparte coined the name in 1991 on the strength of a measly lower right leg with an oddly thick, weight-bearing middle-of-three toes and much thinner toes flanking it. But its fossils were more than doubled in 2016 with a second leg, this time from the left side, which was more complete than the first one and shed some light on its cursorial capabilities.
Typical of animals built for swift running, the lower leg (tibia) of Velocisaurus is long and slender while its upper leg (thigh) is shorter and bowed. Given that its "long" lower leg measures 14 centimetres from knuckle to knuckle, suggesting a total body length of just 1.5 meters, and its known fossils lack heavyweight hunting tools, chances are Velocisaurus used their pace primarily to evade larger predators. Their toes have straight claws rather than the curved claws found on confirmed predatory dinosaurs that use them to subdue struggling prey. But they may have tackled bite-sized mammals, lizards and insects or been omnivorous or even herbivorous. Without fossilized jaws and teeth associated with a matching leg, it's impossible to deduce dietary preferences.
However, Velocisaurus didn't have such a tough life. In 1991, Rothschild examined 12 foot bones for signs of stress fracture, but none were present.
Typical of animals built for swift running, the lower leg (tibia) of Velocisaurus is long and slender while its upper leg (thigh) is shorter and bowed. Given that its "long" lower leg measures 14 centimetres from knuckle to knuckle, suggesting a total body length of just 1.5 meters, and its known fossils lack heavyweight hunting tools, chances are Velocisaurus used their pace primarily to evade larger predators. Their toes have straight claws rather than the curved claws found on confirmed predatory dinosaurs that use them to subdue struggling prey. But they may have tackled bite-sized mammals, lizards and insects or been omnivorous or even herbivorous. Without fossilized jaws and teeth associated with a matching leg, it's impossible to deduce dietary preferences.
However, Velocisaurus didn't have such a tough life. In 1991, Rothschild examined 12 foot bones for signs of stress fracture, but none were present.
(Swift lizard with a unique foot)Etymology
Velocisaurus is derived from the Latin "velocis" (swift) and the Greek "sauros" (lizard).The species epithet, unicus, means "unique" in Latin, referring to the ususual design of its foot.
Discovery
The first remains of Velocisaurus were discovered in the Bajo de la Carpa Formation at Boca del Sapo, Neuquén province, Patagonia, Argentina, by Oscar de Ferrariis and Zulma Brandoni de Gasparini in 1985.
The holotype (MUCPv 41) is the lower part of a right leg. The virtually complete left leg of a second specimen (MPCN-PV-370) from the Bajo de la Carpa Formation at Paso Córdoba in Argentina's Río Negro Province was described in 2016, and confirmed that Velocisaurus—with their very short, stout, and bowed thighs compared to very long and slender lower leg bones—really were swift lizards.
