Troodon

Smartest Dino in the House

During the late Cretaceous period the Earth saw one of the most intelligent dinosaurs to ever live: the Troodon. This somewhat bird like dinosaur, while small, has made a significant impact on paleontology due to this dinosaur’s brain size in comparison to its body size as well as its significantly bird like features. As a result of its bird like features the Troodon seems to have bridged many gaps in paleontology between the reptiles that walked the Earth during the time of the dinosaurs and the birds which survived the massive extinction event at the end of the Cretaceous period.

One of the First Dinosaurs Discovered

The Troodon walked the Earth some 75 – 65 million years ago during the end of the Cretaceous period and was one of the very first dinosaur specimens discovered in North America in 1855. The Troodon varied as far as species and for this reason it was a particularly widespread dinosaur with fossils being found throughout the United States, some as far north as Alaska and some as far south as Texas and New Mexico. The Troodon is named after the Greek words for “wounding tooth”; this name was given to it as a result of its extremely serrated teeth which were certain to inflict serious damage upon prey.

The Troodon was Likely Omnivorous

The Troodon was not a particularly large dinosaur, standing at around 3.3 feet tall and measuring approximately 8 feet long due to its large tail. On average it weighed in at around 60 to 90lbs. It had particularly thin hind legs which enabled it to run rapidly like many other smaller Theropods. The Troodon also had feet much like the Velociraptor of Asia with larger sickle-shaped claws on the second digits of the feet that were raised above the ground when the dinosaur was running; however, unlike the Velociraptors the Troodon’s sickle-shaped claws were retractable. It is likely from examination of its teeth and the presence of such large sickle-shaped claws that the Troodon was omnivorous.

The Troodon had particularly large eyes which suggest they led both diurnal and nocturnal lives and were visual hunters. Its eyes faced forward giving it the ability of depth perception which enabled it to act as a swift hunter. While its eyes were particularly large the skull was a smaller and slender shape with a large brain cavity to accommodate its brain. The  brain was particularly large in proportion to its body mass, making the Troodon one of the most intelligent dinosaurs to ever live.

Was the Troodon a Bird Ancestor?

The Troodon has been a matter of contention for some paleontologists as there are many scientists who believe that it was covered in feathers and that it is an ancestor of the modern day bird. There are also those paleontologists who believe that the Troodon was not entirely covered in feathers and resembled a small reptile with few birdlike qualities. To date no feathers have been found on a specimen. However, it is believed that the Troodon descended from the Sinornithoides, which was a feathered dinosaur.

For those scientists that believe the Troodon was a feathered dinosaur they have an understanding that its entire body was covered in feathers and its mouth was actually more of a beak which resembled a goose beak filled with large serrated teeth. These scientists also believe that the Troodon had legs more like those of an ostrich that still had use for the large sickle-shaped claw since it maintained an omnivorous diet. The excitement in assuming that it was a feathered dinosaur lends a clue as to how feathered birds came in to existence; it provides a link between the reptile like lizards of the dinosaurs and the feathered beasts which survived the Cretaceous extinction event.

A Link to the Brooding Nature of Birds

While the question of feathers is unknown the Troodon is known to have been an egg layer after the discovery of a fossilized nest of eggs. The nest was found on “Egg Mountain” in Montana and included elongated oval eggs. Upon examination of the eggs a Troodon embryo was found within one of the eggs. Another nest discovery revealed an adult Troodon nearby suggesting that this dinosaur brooded its eggs.

Much like crocodiles it is understood that the Troodon utilized soil to incubate eggs in an open nest, although it is only thought to have laid two eggs at a time. Much like birds, however, the Troodon is also thought to have sat on its eggs to ensure warmth as well as utilizing soil for warmth. This fact provides another link between the reptilian nature of the Troodon and the brooding nature of birds which would come later.

Was the Troodon a Carnivorous Dino?

The Troodon had unusual teeth for such a small dinosaur, its teeth were serrated making it possible to eat meat; however, they were also similar in shape to those of popular herbivores of the time. This combination of characteristics led paleontologists to believe that it was an omnivorous dinosaur which likely fed on both meat and vegetation. It has been suggested by paleontologists who have focused on study of the Troodon’s teeth that the dinosaur fed on meat rather than bone when it indulged in its carnivorous habits. This assumption of meat versus bone eating comes from the lack of wear on its teeth that would be present in a dinosaur that eats bone as well as meat.

Due to its size it is believed that the Troodon likely fed on smaller mammals, particularly lizards and the like and supplemented that diet with a large amount of plant material and vegetation. One interesting observation in regards to its teeth is the difference between species when classified by location. When paleontologists examined the Troodon teeth found in Alaska they revealed that this particular species had much larger teeth than the species found elsewhere in the United States. The presence of larger teeth in the Alaskan species suggests that the Troodon’s of Alaska had access to larger prey due to an absence of larger Tyrannosaurid to compete for the larger prey items.

Based on the size of teeth, the presence of a sickle-shaped claw and binocular vision paleontologists believe that the Troodon was a predator when it came to its carnivorous diet. Taking in to account the physiological advantages that it had it does not seem logical that this dinosaur was a scavenger. It is likely that the large brain of this small omnivore allowed this dinosaur to easily track down and isolate prey which it could easily grasp with its smaller hands. The hands of the Troodon featured three long digits with a claw that was ideal for grasping prey or small chunks of meat while eating. It is also believed to have possessed partially opposable thumbs on each forelimb. Much like the Velociraptor it is believed that the Troodon utilized its hind claws for either fatally wounding prey or eviscerating it.

Who Named and Discovered the Troodon?

The Troodon was primarily named after the discovery of a single tooth in the Judith River Formation. The name came from Joseph Leidy, an anatomy professor at the University of Pennsylvania and an American paleontologist, in 1856. Its classification was argued among many paleontologists believing that it should belong in the Pachycephalosaur family; however, it was in 1945 that Charles Mortram Sternberg rejected this idea and presented evidence that the Troodon tooth bore too many resemblances to the teeth of carnivorous dinosaurs.

The second specimen of the Troodon was located in Alberta and consisted of a foot, a partial hand and a few tail vertebrae; these items were found by Sternberg in 1932 and based on the large claw of the second digit they were classified as Coeluridae. It was not until further examination that Sternberg discovered that his self named “Stenonychosaurus” had peculiar teeth much like that of the Troodon and he conjectured that they must be related in some form. It wasn’t until 1969 that a much more complete Stenonychosaurus specimen was found by Dale Russell in the Dinosaur Park Formation. This much more complete specimen enabled paleontologists to paint a much more complete picture of what the Stenonychosaurus looked like.

In 1987 Phil Currie reevaluated the Stenonychosaurus jaw and determined that differences in the jaw of the Stenonychosaurus and that of the Troodon seemed only to be based on age and positioning differences of teeth within the jaw of each dinosaur and consequently he reclassified the Stenonychosaurus as a synonym for the Troodon.

Where Are Troodon Fossils Found?

Fossils of the Troodon appear to be fairly widespread across the United States with fossils being located in Montana, Alberta, Alaska, Texas and New Mexico. While this particular dinosaur has been found throughout these areas, however, it is more widely believed that the smaller omnivores much preferred the areas with a cooler climate and were more able to thrive in the cooler temperatures.

There is not currently enough evidence of the extent of variety in the Troodon species to determine whether a particular species was more able to thrive in an area like Alaska, although it is suggested that the species of Alaska were at least more adapted to eating larger prey. Whether the larger toothed Troodon of Alaska is simply the very same species which roamed the Earth in areas of Texas and Montana with a few evolutionary changes, is unknown. It could perhaps have been that the lack of large Tyrannosaurids to compete for prey allowed the single species of Troodon to develop larger teeth to enable the eating of larger prey.

It could also be, however, that the Troodon of Alaska was a completely different species of Troodon than those found in Texas and Montana and that this particular species simply preferred the colder climates found up in Alaska. It could be that the Alaskan species had larger teeth because it was a larger species.

There are many unknowns in regards to this incredibly intelligent dinosaur; however, one thing that cannot be contested is the intelligence level of this omnivorous beast. Paleontologists are able to estimate the intelligence quotient of dinosaurs based on the size of the brain casings of fossilized specimens. The size of these brain casings is then compared to the size of the fully grown dinosaur as a whole and the intelligence quotient is determined. For its size the Troodon had a significantly large brain case and is one of the, if not the single, most intelligent dinosaurs known to man.

Unfortunately for the Troodon there are very few specimens of this small omnivore to provide detailed information in regard to many aspects of its life. Such details that could certainly benefit from further discovery of more complete specimens include whether or not it was a feathered or scaled dinosaur. Such a discovery would have to include a Troodon specimen complete with feathers or at least a fossilized imprint of feathers, and would most certainly prove a correlation between the transition from reptile to avian. There are, however, certain facts that cannot be debated such as the size of the brain casing, the presence of the large claw on the second digit and the unique teeth.

The facts which are known and have paleontological proof behind them such as its intelligence quotient, its carnivorous capability,  and the omnivorous nature of the teeth of the Troodon provide a basis from which paleontologists can begin to build a picture of this dinosaur. While the Troodon may have quite a few more pieces that need filling in than other dinosaur specimens that have been discovered in larger quantities, enough is known about this small omnivore to know that it was significantly different to its predecessors. The Troodon was different enough to have evolved in to a dinosaur that was intelligent enough and skilled enough to survive in colder climates where predation was less and food was more plentiful.