The animals were found to be able to descend large distances by coasting downward, with no active propulsion.
No other animals were found in the chamber that might hint at when the human relative got there.
The remains of the animals were found alongside bones of small prehistoric crocodiles and huge herbivorous cousins of diplodocus.
He said that newly dead animals were found on each of the group's three expeditions.
Eight dead animals were found nearby on Sunday and two others on 7 July.
However, in the bright, streamlined, industrial world of postwar agriculture, too many of these animals were found wanting in terms of modern productivity.
No injuries were reported, but some pelicans and other animals were found covered with oil, said Roland Guidry, a state oil spill response coordinator.
The animals were found when local fishermen noticed a strange smell emanating from the vessel, which did not have any registration plates, on Tuesday, the Guangzhou Daily reported.
The authorities say their home on Burning Hollow Road, where the animals were found in practically every room, including the basement, is the subject of foreclosure proceedings.
(In July, after a number of Internet-connected smart dolls and stuffed animals were found to harbor security flaws, the F.B.I. released a public-service announcement warning about "opportunities for child identity fraud").
The animals were found in April 2003 at Tiger Rescue and at the house of its owners, John Weinhart, 61, and his wife, Marla Smith, 48, in Glen Avon, a community 10 miles west of here in Riverside County.
