Paleontologist Alan Titus, who discovered the Rainbows and Unicorns site in 2014 and is one of the lead authors of the
PeerJ study, says that the group of deceased and fossilized Tyrannosaurus rex specimens were the victims of a massive flood that drowned them and washed their bodies into a lake. They lay on the bottom, grouped together and undisturbed, for millions of years, until climatological and geological changes dried the lake and created a river (also now gone) that eroded the soil and brought the bones back up to the earth’s surface.
“We used a truly multi-disciplinary approach (physical and chemical evidence) to piece the history of the site together,” explained Celina Suarez , a University of Arkansas geologist and study participant. “The end-result [was] that the tyrannosaurs died together during a seasonal flooding event.”