MANILA, Philippines - Scientists have discovered several new animal species in the Sierra Madre mountain range.

A report on abs-cbnnews.com, citing a paper published last Feb. 7 in ZooKeys journal, said more than a hundred animal species were recently documented by a team led by American Rafe Brown of the University of Kansas.

The research team, composed of American, Filipino and Dutch scientists, found 29 amphibians, 30 lizards, two freshwater turtles, three marine turtles and two crocodilians.

They also found 35 snakes, including the Philippine cobra, Philippine cylindrical snake and a venomous pit viper.

Two forest frogs that were earlier declared endangered by the International Union for Conservation of Nature (IUCN) were also found on the mountain range. Other amphibians found in the area are also on the IUCNâ€™s â€œnear threatenedâ€ list.

Brown said 38 percent of the recorded species are â€œassociated with unresolved taxonomic issues or suspected new species or species complexes in need of taxonomic partitioning.â€

â€œThis suggests that despite past and present efforts to comprehensively characterize the fauna, the herpetological biodiversity of the northern Philippines is still substantially underestimated and warranting of further study,â€ the report quoted Brown as saying.

It said the study was based on surveys and museum records in the towns of Gonzaga, Gattaran, Lasam, Santa Ana and Baggao in Cagayan province and Cabagan, San Mariano, and Palanan in Isabela.

Brown said a majority of the discovered animal species could only be found in the Philippines. He said it proves that â€œherpetological diversity of the northern Philippines is far more diverse than previously imagined.â€