TROODONTIDAE

This group of maniraptorans has a long history that reaches back into the Late or perhaps Middle Jurassic. Most finds come from the Late Cretaceous of Mongolia, but remains from North and South America, perhaps even Africa, indicate a much wider distribution of these fast-running omnivores. It seems that troodontids were relatively common in the northern continents until the middle Oligocene or so [or whenever!], when their characteristic teeth with their coarse serrations vanish from the fossil record. [Brian's essay on troodontid extinction, please!]

The only two living species, the nandrakes (Notocursornis maior and N. minor), were at first quite a puzzle to systematists, because they have long lost the sickle claw of their ancestors, various skeletal details (such as the shape of the pelvis) differ appreciably from any known fossil troodontid of both timelines and don't resemble anything else either, and their DNA does not suffice to assign them to something more precise than Maniraptora. Some wondered if a weird mattiraptor had managed to cross the Atlantic Ocean; the nandrakes differ from mattiraptors, however, in their larger number of teeth, the constriction between the root and crown of these, and in peculiarities of the vertebrae. Today's consensus is that nandrakes are genuine troodontids which have survived in southern South America, although some scientists are still not entirely comfortable with this idea.

The greater nandrake (Notocursornis maior) is the more common of the two nandrake species. It is a common sight in the pampas of South America, running across the grassland in groups of 10 to 20. At a length of some 2.3 m, the greater nandrake is slightly larger than its principal enemy, the cazarrino. As a good long-distance runner, it has usually not much to fear; nandrakes have also been seen delivering nasty kicks with their long feet and leashing out with their clawed hands. Nandrakes themselves eat pretty much everything they can take a bite of, from herbs, grass and seeds over small mammals and lizards to the eggs and nestlings of levantadores and kentropods as well as carrion. Nandrake nests are quite large; it is not a rare occurrence to find 40 eggs in one, hidden in the grass and brooded by the male.

(fig. 1) Greater nandrake, Notocursornis maior [what about even more cursorial feet?]

David Marjanović