1877 in paleontology

O. W. Lucas collected the first remains of what would later in the year be named Laelaps trihedrodon from Quarry I of the Saurian Hill at Garden Park, Colorado.[4] Edward Drinker Cope would describe the material later in the year in a short paper titled "On a carnivorous dinosaurian from the Dakota beds of Colorado."[5] The "Dakota beds" he references are actually Morrison Formation strata.[4] Cope claims to have a skeleton of unspecified completeness on which to establish the new species, but only describes a partial dentary which has 5 successional teeth, 2 functional teeth, and one tooth missing from its socket.[5] All of the preceding material has since been lost to science with the exception of 5 broken, partial tooth crowns.[6] From the now missing dentary, Cope infers that the creature is a carnivore and compares its dentition to that belonging to other members of his infamous genus "Laelaps", L. aquilunguis and L. incrassatus.[5] Cope concludes the paper with a pointed criticism of his rival O. C. Marsh's attempt to rename Laelaps as the genus Dryptosaurus because the generic name Laelaps has been used in entomology.[7] Cope claims that since the mite genus Laelaps was a synonym that the name was not truly preoccupied and Marsh's erection of Dryptosaurus has therefore created a new, redundant synonym of Laelaps the dinosaur.[7] However, subsequent researchers have supported Marsh's new name.

• Apatosaurus specimen found with preserved gastroliths.[8]