Pectinodon

## PectinodonComb Tooth

* Male
* Juvenile

* **Adult tooth length** of 6.2 millimeters (0.24 inches)
* Teeth have comb-like serrations on the rear edges

***“ A family of Pectinodon. They're feathered, but flightless. And they're lead by their father. ”***

― **David Attenborough**, *North America*
***Pectinodon*** (Comb Tooth) is a genus of troodontid theropod dinosaur that lived in western North America 67 - 66 million years ago, during the Maastrichtian stage of the Late Cretaceous Period.

## Description

### Dentition

*Pectinodon* is only known from a 6.2-millimeter (0.24-inch) tooth that belongs to a mature individual and three teeth that belong to juveniles. The teeth have comb-like serrations on their back edges, hence the dinosaur's name, "comb tooth". Based on these teeth, it is believed that *Pectinodon* is a small troodontid barely 1.8 meters (6 feet) long.

### Prehistoric Planet's Depiction

On Prehistoric Planet, *Pectinodons* are shown to be mostly covered in brown feathers, with the feathers lining their arms being a darker shade of brown. The males are shown to have white stripes running from their top and bottom jaws, over their shoulders, down to their white undersides. What may be females or younger males are also shown with no white stripes running from their jaws, an underside with the same shade of brown as the rest of their bodies, and small, white feathers lining the dark brown ones on their arms. The juveniles are depicted with a white coat, speckled with black markings, their snouts bare, revealing the black scales beneath.

## Habitat

*Main: Hell Creek Formation*

Main: Hell Creek Formation

***“ These coastal seas are full of life. Yet on land, and only a few hundred miles away, there is desolation. Here, powerful movements deep in the Earth's crust are beginning to raise the Rocky Mountains. The immense changes in the landscape have cut off this lake from nearby rivers. Its waters evaporate in the strong winds and intense summer sun, and the minerals that have dissolved in it are beginning to reach toxic levels. For most, this water is simply too poisonous too drink. Even so, every year, this place is visited by all kinds of animals. ”***

― **David Attenborough**, *North America*
*Pectinodon* lived 67 - 66 million years ago in Laramidia, an island continent that would one day become western North America, which, by that time, was split in half by an inland sea. Remains have been excavated from the Hell Creek Formation in Montana and South Dakota, and the Lance Formation in Wyoming. These two formations show that the sort of world that *Pectinodon* lived in was one dominated by rivers, forests, and coastal plains, regions kept constantly humid by ample rainfall and a subtropical climate warmer than those areas are today (hence, there was no cold season in those areas back then).

Prehistoric Planet depicts *Pectinodon* as visiting a lake hundreds of miles from the sea, slowly evaporating and degrading into toxicity due to the same tectonic movements raising the Rocky Mountains. This soda lake is depicted as being in the Denver Formation of Colorado. Little is known about the area, and *Pectinodon* fossils have yet to actually be found there. However, deposits indicate that there were floodplains, marshes, and rivers that formed by the foot of the growing Rocky Mountains during that time, and the existence of *Pectinodon* in other areas of the US outside of the Hell Creek and Lance Formations is somewhat plausible.

## Behavior

***“ Pectinodon are particularly intelligent dinosaurs. It doesn't take them long to work out the best way to collect flies. ”***

― **David Attenborough**, *North America*
*Pectinodons* are shown to be opportunistic hunters like any other predator, with a trio of them (or closely-related troodontids) closing in on the smell of an *Alamosaurus* carcass, and one briefly risking its life to grab a piece of meat from the carcass while a *Tyrannosaurus* is feeding on it before running off. This opportunistic behavior is again seen when a family of *Pectinodon* visit an evaporating toxic lake. As troodontids, *Pectinodons* are shown to be particularly intelligent dinosaurs. The juveniles feed on flies living around the lake, eventually working out that the best way to eat as many as they can is to rush at the flies with their jaws fully agape.

***“ Pectinodon are not only intelligent, they're also very skillful hunters. ”***

― **David Attenborough**, *North America*
While the juveniles go after flies, their father, staying low and hidden behind the rock and mineral pillars surrounding the lake, ambushes and grabs one of the "Styginetta" that also came to feed on the flies. As with Prehistoric Planet's depiction of *T. rex*, juvenile *Pectinodons* are only lead and cared for by their father.

## Appearances

### North America

#### Segment 1

***“ Dawn. And these troodontids have picked up a scent. They're quick to investigate anything new, especially if it might be worth eating. But biting through a three inch-thick hide is beyond their power. Very frustrating. ”***

― **David Attenborough**, *North America*
In the first segment of the North America, as a herd of *Alamosaurus* travel along a beach, one of them collapses due to his great age and passes away. The next day, a trio of troodontids (which may or may not be *Pectinodon*) discover the corpse, but frustratingly find themselves unable to bite through the titanosaur's hide, which is three inches thick. The troodontids are then scared away by a male *Tyrannosaurus*, which is easily able to feed on the carcass with his six-inch teeth and bone-crushing bite. One troodontid manages to take one strip of meat as the T. rex feeds before being forced away again.

#### Segment 3

In the third segment of North America, many animals are shown visiting an evaporating toxic lake for feeding opportunities. Among them, "Styginetta", a primitive relative of ducks, and a family of dinosaurs. Six juvenile *Pectinodons* poke out from the rocks, lead to the toxic lake by their father.

***“ These dinosaurs and the Styginetta are both drawn here by a strange seasonal bonanza. Flies. The larvae of these insects are able to filter out the lake's toxic salts, and, as a consequence, they thrive in immense numbers. Now, they're hatching into adults in their millions. They are a rich and abundant source of protein for all the lake's visitors. ”***

― **David Attenborough**, *North America*
Watching millions of flies and emerging from the lake, the juvenile *Pectinodons* jump up and snap at the flies, but they soon eventually figure out that the best way to scoop up as many flies as possible is by rushing at them, stirring the flies like dirt from the ground, with their jaws gaping open to collect them in mouthfuls. A flock of "Styginetta" watch as the juveniles run around gulping flies, which eventually ends up with two of the juveniles crossing each other's paths while rushing, causing them to collide and get knocked to the ground. While all this is happening, however, the father of the *Pectinodon* chicks closes in on one "Styginetta" flock from behind, slowly approaching the birds while staying low, obscured by the rock and mineral pillars around the lake. By the time the birds realize he is there, the flock taking to the air, the *Pectinodon* leaps up and catches one by the throat in midair, swinging and slamming his prey twice to the ground before finishing off the bird with another bite.

***“ Success. A rather more substantial meal for the family, and just as well. The flies will only be here for so long, and the dinosaur family will be forced to find food elsewhere. ”***

― **David Attenborough**, *North America*
As the "Styginetta" fly off, with many other flocks of them still ankle-deep in the lake, looking for flies to eat, the *Pectinodon* father brings his catch to his six chicks, the family settling down to eat as flocks of "Styginetta" fly overhead.

## Trivia

* It was never confirmed if the troodontids in the first segment of North America (set in the Javelina Formation) were *Pectinodon*, and given how they were simply referred to as "troodontids", it is possible that they were indeed meant to be a different species, as *Pectinodon* itself isn't known from the Javelina Formation.
	+ It is possible for related animals to have similar coats (as the troodontids of the Javelina Formation are shown to have a similar color scheme with only a few differences), though it is also likely that the model of *Pectinodon* was simply recycled for this sequence to save on costs.
	+ The Javelina Formation does have remains classified as "*Troodon sp.*". Currently, *Troodon* is considered a potentially dubious genus due to its remains being considered undiagnostic, with most fossils once referred to it being reclassified as *Stenonychosaurus*, *Latenivenatrix* (which may or may not be a junior synonym of *Stenonychosaurus*), or *Pectinodon*. With the identity of the Javelina Formation troodontid still undetermined, the existence of *Pectinodon* itself in Texas (and, by extension, other areas in the US) is very much plausible.
* The third segment of North America, which features *Pectinodon* in the Denver Formation, was shot in Mono Lake, Mono County, California, USA (North America, Segment 3)

## References

1. ↑ 1.0 1.1 I Know Dino: The Big Dinosaur Podcast, Episode 447: Dinosaurs in North America: Featuring Prehistoric Planet 2
2. ↑ Raynolds, R.G. 2002. Upper Cretaceous and Tertiary stratigraphy of the Denver Basin, Colorado. Rocky Mountain Geology, vol. 37, no. 2, p. 111-134.