S72 - Exceedingly Rare Zapsalis abradens (Dromaeosaurid Raptor Theropod) Dinosaur Tooth - Judith River Fm

Zapsalis is a genus of extinct dromaeosaurid coelurosaurian dinosaur known primarily from teeth found in the Late Cretaceous Judith River Formation of Montana and Wyoming.

Identification: Very compressed tooth with rounded serrations on the distal side and smooth mesial edge. One flat tooth surface with longitudinal ridges. The unserrated form of this tooth (Paronychodon morph) may also be a premaxillary tooth of a Dromaeosaurid or Troodontid. New discoveries are needed to properly assign it.

 The formation: which dates back approximately 75 to 79 million years, has also yielded nearly complete remains of other dinosaurs, but Zapsalis is known only from fragmentary teeth. The identification of Zapsalis from these teeth has been debated, but some paleontologists recognize it as a valid taxon, distinguishing it by a unique combination of rounded denticles and straight edges.

Zapsalis and the Judith River Formation
Judith River Formation: This geological formation in Montana and Wyoming is a dinosaur-rich fossil site from the Late Cretaceous period, known as the "Judithian Age of Terrestrial Vertebrates."

Discovery of the genus: The name Zapsalis was coined in 1876 by Edward Drinker Cope from teeth found in the Judith River Formation.

Tooth characteristics: Zapsalis teeth are characterized by rounded denticles on their edges, a straight posterior margin, and vertical grooves, according to several studies.

Genus status: Because only fragmentary teeth have been found, the genus is often considered doubtful or "dubio."

Current recognition: Despite the doubts, some paleontologists consider the teeth from the Judith River Formation (and the Dinosaur Park Formation) to be valid and to represent a unique dromaeosaurid taxon.

Taxonomy: It is generally classified as a dromaeosaurid theropod dinosaur.

Other fossils: The Judith River Formation has also yielded fossils of other dinosaurs, including the hadrosaurid Brachylophosaurus and several ceratopsians and tyrannoaurids.

The tooth comes stored in a display box.