Alphadon (Dinosaur Toys).


Alphadon (Greek for "first tooth"); pronounced AL-fah-don


Woodlands of North America

Historical Period:

Late Cretaceous (70 million years ago)

Size and Weight:

About one foot long and 12 ounces


Insects, fruit and small animals

Distinguishing Characteristics:

Long, prehensile tail; long hind legs

About Alphadon

As is the case with many of the early mammals of the Mesozoic Era, Alphadon is known primarily by its teeth, which peg it as one of the earliest marsupials (the non-placental mammals represented today by Australian kangaroos and koala bears). Appearance-wise, Alphadon probably resembled a small opossum, and despite its tiny size (only about three-quarters of a pound soaking wet) it was still one of the largest mammals of late Cretaceous North America. Befitting its small stature, paleontologists believe that Alphadon spent most of its time high up in trees, well out of the way of the stomping tyrannosaurs and titanosaurs of its ecosystem.

At this point, you may be wondering how a prehistoric marsupial ended up in North America, of all places. Well, the fact is that even  modern marsupials aren't restricted to Australia; opossums, to which Alphadon was related, are indigenous to both North and South America, although they had to "reinvade" the north about three million years ago, when the Central American Isthmus rose up and connected the two continents. (During the Cenozoic Era, after the demise of the dinosaurs, huge marsupials were thick on the ground in South America; before their extinction, a few stragglers managed to find their way via Antarctica to Australia, the only place today where you can find plus-sized pouched mammals.)