LEWISTON - Four high school seniors working in a cemetery Monday unearthed two intact animal skeletons.

Speculation about the bones' origin ranged from skunk to Tyrannosaurus Rex before an expert ruled they belonged to dogs.

The St. Dominic Regional High School students, who have volunteered since April at Mount Hope Cemetery off Lincoln Street, had been tearing down an old maintenance shed at the top of a hill.

When they ripped up the floor of the shed and uncovered the partially concealed bones, one of the students pointed and said: "Look there's a skull and (the other boys) said, 'Ah, sick,'" said Codie Keene, a student at St. Dominic Regional High School in Auburn.

They laid out the skeletons on a sheet of plywood and set them safely aside. Fur still clung to the hind legs and tail of one of the skeletons.

The students later discovered another pile of bones among rotted timbers and cracked concrete blocks. Gently pulling dirt from around the remains like expert archaeologists, they spoke in excited tones about their find, hoping it might be something exotic.

They beckoned their supervisor, who exclaimed the bones might be dinosaur remains.

A world-renowned cryptozoologist from Portland put the guessing to rest. Loren Coleman quickly identified them from photographs as mature dogs.

"The indications of this verdict are the relatively intact hind paw visible on one carcass, the skull structure, skeletal configurations and the size of the overall carcass," he wrote in an e-mail.

He compared the photographs to a common dog skull and other commonly found animal skulls to confirm his verdict.

The four seniors started helping out at the cemetery on April 28 and will complete their so-called "Senior Involvement" on May 20, said Anne Pontbriand, who coordinates the program at the Auburn school.

High school students volunteer 5½ hour each day over a 3½-week period at the end of their senior years, she said. Others among the 71 graduating seniors have volunteered at hospitals, food pantries and schools, she said.