US researchers who found a toad crawling on the bottom of Loch Ness said their most important discovery had been the remains of an ancient seabed.
The toad was spotted crawling 300ft (91m) down
Experts from the Massachusetts Institute of Technology (MIT) have been surveying the loch.
Lecturer Bob Rines will tell a conference in Aberdeen next month that carbon dating of the remains revealed they were 12,800 years old.
The common toad was also spotted 324ft (98m) down during the survey.
Mr Rines will present a paper to the Oceans 07 conference in Aberdeen on its work on Loch Ness.
He hopes others will make use of data and targets - objects picked up in the survey, such as animal remains - gathered by MIT's Academy of Applied Sciences.
In a briefing on the paper, MIT said: "The academy invites United Kingdom university and other research teams to use our mapped data of these targets in helping identify the further secrets - geological, animal, man-made and maybe hysterical - that are waiting to be revealed.
"Perhaps the most important discovery to date is the remains of an ancient seabed, recoveries from which we have been able to carbon date back to the date of the melting of the last glacier 128 centuries ago."
MIT said the run-off from the melting glacier was at least one of the entries of the sea into the loch.
Loch Ness Monster
Information amassed so far has been compared with a geological map of the bottom made by Sir Edward Murray using plumb lines 100 years ago.
The toad was spotted during the MIT survey.
Scientists at Scottish Natural Heritage (SNH) have been intrigued by the amphibian's ability to move around at such a depth and its sighting has sparked a "healthy debate".
SNH said the toad's appearance was scientifically more interesting than speculation on the presence of a Loch Ness Monster.