April 4, 2022 Scott Kraus

Microvenator Was an Oviraptorosaurian Theropod

This “small hunter” is a genus of reptilian dinosaur, or oviraptorosaurian theropod.  Microvenator is one of the smallest Theropods to exist.  Like other oviraptorosaurs, Microvenator was a feathered maniraptoran dinosaur from the Cretaceous Period.  They both have the characteristic short beaked snout and bird-like skull.  The size of oviraptorosaurs could vary, with the group exhibiting a range of turkey-sized animals to some over 24 feet long.  While most oviraptorosaurian fossil remains have been found in Asia, lonely Microvenator was found in North America, in the state of Montana.  The type species is Microvenator celer.

Quick Facts

What Did Microvenator Look Like?

This small dinosaur was the size of a large dog or turkey, with shorter arms on front than legs on back but still the arms were very long—almost as long as the rear, but not utilized as quadrupedal elements.  Microvenator moved in bipedal fashion, and possibly was winged on the front limbs.  Large eyes long neck, small head, long snout, beaked—all the traits of many birds.   Each hand had 3 long fingers each with a claw.  Each foot had three clawed birdlike toes.  The beak occupied half the portion of skull length.

What Did Microvenator Eat?

Microvenator was a carnivorous predator that existed during the Late Cretaceous Period and probably subsisted on insects, small rodent-like animals, reptiles and other small meaty sources.

How Did Microvenator Move?

Microvenator was likely a fast-moving dinosaur, with its light body and long legs.  Although the front limbs are considered short (shorter than the rear limbs), they were long in comparison with other dinosaurs said to have “long forelimbs”.  Legs were long and bird-like, though Microvenator was a lizard-hipped Saurischian dinosaur.  Microvenator would have been light and quick, and could have been one of the primitive flightless birds.  Microvenator was of the order Coelurosauria, which were fast, lightly built predators with hollow bones.

Where did Microvenator Live?

Early Cretaceous layer discoveries suggest that Microvenator lived…  lived in the time of… 119—113 billion years ago.  Earth had not yet cooled and was much warmer than it is now.  There were no polar ice caps at this time, and sea levels were at all-time highs, though continental drift had already occurred so that the separate land masses effectively caused new climates to any inhabitants.

Today, the area where Microvenator is found is the familiar and modern state of Montana.  The popular Cloverly Formation in South Central Montana has turned tourism into an exciting dinosaur adventure for those so inclined.  While museums accumulate and have been prevalent in the area for some time, it was more recently that the region’s Missouri river Country board of directors formulated the plan for The Montana Dinosaur Trail as a way to improve museums awareness and attendance and to enhance tourism.  The trail is a series of fourteen dinosaur themed attractions including museums and state parks, among others.  The enrichment opportunities span over twelve of the area communities.

The teamwork of many area officials and groups culminated in the May 2005 opening of Dinosaur Trail in Montans.  Visitors are rewarded for repeat visits via a “Prehistoric Passport”.  Thanks to the tourism drive of The Montana Dinosaur Trails project, the area has seen an increase in visitation, and area businesses of all kinds have benefited.

Although many dinosaur fossils have been found in Montana rich Late Cretaceous layers, there is only one Microvenator.

The Discovery of Microvenator

The only definite recovered fossil of Microvenator is about four feet long; however, it is believed that the Microvenator type specimen is one of a young dinosaur.  After calculations based on what was recovered, it is estimated that the Miccrovenator adult was nearer to 10 feet long.  The remains included parts of a skull, hand, foot, one fibula and 23 vertebrae along with four ribs and several other tell-tale bone pieces.

The type specimen was taken from the earth in 1933 and included teeth.  At first, Microvenator was given credit for a fairly large head when compared to its body.  The specimen was casually referred to at the time as “Megadontosaurus”; however this would not stick, since the name was never officially published.  It wasn’t until 1970 that the type specimen was described officially.  Discovered and recovered by Barnum Brown (curator of the American Museum of Natural History), it took years of tedious subsequent study by other scientists before finally John Ostrom (US paleontologist and author) accumulated enough observation to make a determination.  It was confirmed that Microvenator is the earliest known member of the oviraptorosaurian group collected from North America.  Ostrom is the first scientist to champion the theory of modern birds evolved of Theropod dinosaurs. Oviraptorosaurs like Microvenator are so bird-like that many scientists regard them as true birds.  For now however, Microvenator and other Oviraptorosaurs remains classed as non-avian maniraptorans.

Microvenator Probably Did Not Eat its Own Eggs!

Once considered “Egg thief lizards”, Microvenator and other Oviraptorosaurs were thought to have raided the nests of other species, based on a Mongolian find showing Oviraptor on top of a nest.  However, recent studies have shown that in fact the animal was on top of its own nest.