Manatees do not stay year-round in Texas, however these mild, slow-moving sea cows are identified to often go to, swimming in for a “summer time trip” from Florida and Mexico and returning to hotter waters for the winter.
Analysis led by The College of Texas at Austin has discovered fossil proof for manatees alongside the Texas coast courting again to the latest ice age. The invention raises questions on whether or not manatees have been making the go to for hundreds of years, or if an historic inhabitants of ice age manatees as soon as known as Texas house someplace between 11,000 and 240,000 years in the past.
The findings had been revealed in Palaeontologia Electronica.
“This was an surprising factor for me as a result of I do not take into consideration manatees being on the Texas coast at present,” mentioned lead writer Christopher Bell, a professor on the UT Jackson College of Geosciences. “However they’re right here. They’re simply not well-known.”
The paper co-authors are Sam Houston State College Pure Historical past Collections curator William Godwin, SHSU alumna Kelsey Jenkins (now a graduate pupil at Yale College), and SHSU Professor Patrick Lewis.
The eight fossils described within the paper embrace manatee jawbones and rib fragments from the Pleistocene, the geological epoch of the final ice age. Many of the bones had been collected from McFaddin Seashore close to Port Arthur and Caplen Seashore close to Galveston in the course of the previous 50 years by beginner fossil collectors who donated their finds to the SHSU collections.
“We’ve got them from one decade to a different, so we all know it isn’t from some outdated manatee that washed up, and now we have them from completely different locations,” Godwin mentioned. “All these strains of proof assist that manatee bones had been arising in a continuing manner.”
The Jackson Museum of Earth Historical past at UT holds two of the specimens.
A decrease jawbone fossil, which was donated to the SHSU collections by beginner collector Joe Liggio, jumpstarted the analysis.
“I made a decision my assortment can be higher served in a museum,” Liggio mentioned. “The manatee jaw was certainly one of many unidentified bones in my assortment.”
Manatee jawbones have a definite S-shaped curve that instantly caught Godwin’s eye. However Godwin mentioned he was met with skepticism when he sought different manatee fossils for comparability. He remembers reaching out to a fossil vendor who informed him point-blank “there aren’t any Pleistocene manatees in Texas.”
However examination of the fossils by Bell and Lewis proved in any other case. The bones belonged to the identical species of manatee that visits the Texas coast at present, Trichechus manatus. An higher jawbone donated by U.S. Rep. Brian Babin was discovered to belong to an extinct type of the manatee, Trichechus manatus bakerorum.
The age of the manatee fossils relies on their affiliation with better-known ice age fossils and paleo-indian artifacts which have been discovered on the identical seashores.
It is assumed that the cooler ice age local weather would have made Texas waters even much less hospitable to manatees than they’re at present. However the truth that manatees had been in Texas — whether or not as guests or residents — raises questions concerning the historic setting and historic manatees, Bell mentioned. Both the coastal local weather was hotter than is mostly thought, or ice age manatees had been extra resilient to cooler temperatures than manatees of at present.
The Texas coast stretched a lot farther into the Gulf of Mexico and hosted wider river shops in the course of the ice age than it does now, mentioned Jackson College Professor David Mohrig, who was not a part of the analysis group.
“Subsurface imaging of the now flooded fashionable continental shelf reveals each a larger variety of coastal embayments and the presence of considerably wider channels throughout ice age instances,” mentioned Mohrig, an knowledgeable on how sedimentary landscapes evolve.
If there was a inhabitants of ice age manatees in Texas, it is believable that they might have rode out winters in these hotter river shops, like how they do at present in Florida and Mexico.