The towering waves that killed more than 285,000 people throughout Asia also appear to have swept a bronze Buddha to Indian shores from Thailand in a basket attached to a bamboo raft, they said.
Archaeologists from the Archaeological Survey of India (ASI) have descended on the ancient seaport of Mahabalipuram, famed for its rock carvings dating back to the great Pallava dynasty, to see the objects.
"The sea has thrown up evidence of the grandeur of the Pallava dynasty. These have been buried for centuries," the archaeological body's superintending archaeologist, T Sathiamoorthy, said on Thursday.
"We're all very excited about these finds."
The Hindu dynasty dominated much of South India from as early as the first century BC to eighth century AD and Mahabalipuram is now recognised as the site of some of the greatest architectural and sculptural achievements in India.
The archaeologists are also excited about a report from locals that just before the waves struck on 26 December, the sea withdrew a great distance baring the seabed on which lay a temple structure and several rock sculptures.
Among the tsunami "gifts" found in Mahabalipuram, 70km south of Madras, are the remnants of a stone house and a half-completed rock elephant, archaeologists say.
The tsunami uncovered priceless
relics buried under sand
There are also two giant granite lions, one seated and another poised to charge. The statues are each carved out of a single piece of granite stone, testifying to the carver's skill.
The objects were uncovered when the towering waves withdrew from the beach, carrying huge amounts of sand with them.
"We'll be exploring the seabed to document these Pallava relics," Sathiamoorthy said, adding the Archaeological Survey of India would dispatch a team of marine archaeologists next month to the area.
Experts are also examining a 15cm tall bronze Buddha found inside a bamboo basket attached to a raft to determine its age and origin. The figure with Myanmarese writing on its back is seated lotus style and holds a begging bowl on his lap.
"It seems it might have been taken to Thailand from Burma [Myanmar] at some point and then was carried out to sea by the tsunami," said B Sasisekaran, a scientist at the National Institute of Ocean Technology.
While Myanmar suffered some damage from the tsunamis, oceanographers think the way the waves travelled east to west suggests the Buddha came from the coast of Thailand, which is a Buddhist country.
Fishermen have put the statue inside a Hindu temple.
"The sea has thrown up evidence of the grandeur of the Pallava dynasty. These have been buried for centuries"
T Sathiamoorthy, archaeologist, Archaeological Society of India
Cartographers say the waves that left nearly 16,400 dead or missing in southern India and the country's far-flung Andaman and Nicobar islands have redrawn the entire Mahabalipuram coastline.
One of a clutch of temples is partly submerged. But the magnificent eighth century Shore Temple, a UN World Heritage Site famed for its carvings representing characters from Hindu scriptures, survived the sea's fury.
This was thanks to a move by India's then prime minister, Indira Gandhi, who ordered that huge rocks be piled around the building to protect it from sea erosion after visiting the site in the late 1970s, officials said.