Vertebrate palaeontology: Long night for owl monkeys.
D000818:Animals; D001029:Aotus trivirgatus / Q000033:anatomy & histology*; D002427:Cebidae / Q000033:anatomy & histology*; D002940:Circadian Rhythm; D005580:Fossils; D010163:Paleontology; D012886:Skull / Q000033:anatomy & histology; D013045:Species Specificity