Showing posts with label texas. Show all posts
Showing posts with label texas. Show all posts

Wednesday, May 22, 2024

MANATEE: PLEISTOCENE TEXANS

Manatees do not live year-round in Texas, but these gentle sea cows are known to occasionally visit, swimming in for a summer vacation and returning to warmer waters for the winter. 

Interestingly, we have recently found fossil evidence for manatees along the Texas coast dating back to the most recent ice age. 

The discovery raises questions about whether manatees have been visiting for thousands of years, or if an ancient population of ice age manatees once called Texas home.

The findings were published in Palaeontologia Electronica by lead author Christopher Bell, a professor at the UT Jackson School of Geosciences with co-authors Sam Houston State University Natural History Collections curator William Godwin and SHSU alumna Kelsey Jenkins — now a graduate student at Yale University — and SHSU Professor Patrick Lewis.

The eight fossils described in the paper include manatee jawbones and rib fragments from the Pleistocene, the geological epoch of the last ice age. Most of the bones were collected from McFaddin Beach near Port Arthur and Caplen Beach near Galveston during the past 50 years by amateur fossil collectors who donated their finds to the SHSU collections.

The Jackson Museum of Earth History at UT holds two of the specimens. A lower jawbone fossil, which was donated to the SHSU collections by amateur collector Joe Liggio, jumpstarted the research.

Manatee jawbones have a distinct S-shaped curve that immediately caught Godwin's eye. But Godwin said he was met with scepticism when he sought other manatee fossils for comparison. He recalls reaching out to a local fossil enthusiast who told him point-blank, "there are no Pleistocene manatees in Texas."

But an examination of the fossils by Bell and Lewis proved otherwise. The bones belonged to the same species of manatee that visits the Texas coast today, Trichechus manatus. An upper jawbone donated by U.S. Rep. Brian Babin was found to belong to an extinct form of the manatee, Trichechus manatus bakerorum.

The age of the manatee fossils is based on their association with better-known ice age fossils and paleo-Indian artefacts that have been found on the same beaches.

It is assumed that the cooler ice age climate would have made Texas waters even less hospitable to manatees than they are today. But the fact that manatees were in Texas — whether as visitors or residents — raises questions about the ancient environment and ancient manatees. The Texas coast stretched much farther into the Gulf of Mexico and hosted wider river outlets during the ice age than it does today. Either the coastal climate was warmer than is generally thought, or ice age manatees were more resilient to cooler temperatures than manatees of today.

Subsurface imaging of the now flooded modern continental shelf reveals both a greater number of coastal embayments and the presence of significantly wider channels during ice age times.

If there was a population of ice age manatees in Texas, it is entirely plausible that they would have ridden out winters in these warmer river outlets similar to how they do today in Florida and Mexico.

Reference: Christopher Bell, William Godwin, Kelsey Jenkins, Patrick Lewis. First fossil manatees in Texas: Trichechus manatus bakerorum in the Pleistocene fauna from beach deposits along the Texas Coast of the Gulf of Mexico. Palaeontologia Electronica, 2020; DOI: 10.26879/1006

Saturday, October 14, 2023

AN UNLIKELY RHINOCEROS AND THE GREAT DEPRESSION

The Miocene pillow basalts from the Lake Roosevelt National Recreation Area of central Washington hold an unlikely fossil. 

What looks to be a rather unremarkable ballooning at the top of a cave is actually the mould of a small rhinoceros, preserved by sheer chance as its bloated carcass sunk to the bottom of a shallow lake just prior to a volcanic explosion.

We have known about this gem for a long while now. The fossil was discovered by hikers back in 1935 and later cast by the University of California palaeontologists in 1948. 

The Dirty Thirties & The Great Depression

These were the Dirty Thirties and those living in Washington state were experiencing the Great Depression along with the rest of the country and the world. Franklin D. Roosevelt was President of the United States, navigating the States away from laissez-faire economics. 

Charmingly, Roosevelt would have his good name honoured by this same park in April of 1946, a few years before researchers at Berkeley would rekindle interest in the site.

Both hiking and fossil collecting was a fine answer to these hard economic times and came with all the delights of discovery with no cost for natural entertainment. And so it was that two fossil enthusiast couples were out looking for petrified wood just south of Dry Falls on Blue Lake in Washington State. 

While searching the pillow basalt, the Frieles and Peabodys came across a large hole high up in a cave that had the distinctive shape of an upside-down rhinoceros.

This fossil is interesting in all sorts of ways. First, we so rarely see fossils in igneous rocks. As you might suspect, both magma and lava are very hot. Magma, or molten rock, glows a bright red/orange as it simmers at a toasty 700 °C to 1300 °C (or 1300 °F to 2400 °F) beneath the Earth's surface.

A Rhinoceros Frozen in Lava

During the late Miocene and early Pliocene, repeated basaltic lava floods engulfed about 63,000 square miles of the Pacific Northwest over a period of ten to fifteen million years. After these repeated bathings the residual lava accumulated to more than 6,000 feet.

As magma pushes up to the surface becoming lava, it cools to a nice deep black. In the case of our rhino friend, this is how this unlikely fellow became a fossil. Instead of vaporizing his remains, the lava cooled relatively quickly preserving his outline as a trace fossil and remarkably, a few of his teeth, jaw and bones. The lava was eventually buried then waters from the Spokane Floods eroded enough of the overburden to reveal the remains once more.

Diceratherium tridactylum (Marsh, 1875)
Diceratherium (Marsh, 1875) is known from over a hundred paleontological occurrences from eighty-seven collections.

While there are likely many more, we have found fossil remains of Diceratherium, an extinct genus of rhinoceros, in the Miocene of Canada in Saskatchewan, China, France, Portugal, Switzerland, and multiple sites in the United States.

He has also been found in the Oligocene of Canada in Saskatchewan, and twenty-five localities in the United States — in Arizona, Colorado, Florida, Nebraska, North Dakota, Oregon, South Dakota, Washington and Wyoming.  

Diceratherium was a scansorial insectivore with two horns and a fair bit of girth. He was a chunky fellow, weighing in at about one tonne (or 2,200 lbs). That is about the size of a baby Humpback Whale or a walrus.

Back in the Day: Washington State 15 Million-Years Ago

He roamed a much cooler Washington state some 15 million years ago. Ice dams blocked large waterways in the northern half of the state, creating reservoirs. Floodwaters scoured the eastern side of the state, leaving scablands we still see today. In what would become Idaho, volcanic eruptions pushed through the Snake River, the lava cooling instantly as it burst to the surface in a cloud of steam. 

By then, the Cascades had arrived and we had yet to see the volcanic eruptions that would entomb whole forests up near Vantage in the Takama Canyon of Washington state. 

Know Before You Go

You are welcome to go see his final resting site beside the lake but it is difficult to reach and comes with its own risks. Head to the north end of Blue Lake in Washington. Take a boat and search for openings in the cliff face. You will know you are in the right place if you see a white "R" a couple hundred feet up inside the cliff. Inside the cave, look for a cache left by those who've explored here before you. Once you find the cache, look straight up. That hole above you is the outline of the rhino.

If you don't relish the thought of basalt caving, you can visit a cast of the rhino at the Burke Museum in Seattle, Washington. They have a great museum and are pretty sporting as they have built the cast sturdy enough for folk to climb inside. 

The Burke Museum 

The Burke Museum recently underwent a rather massive facelift and has re-opened its doors to the public. You can now explore their collections in the New Burke, a 113,000 sq. ft. building at 4300 15th Ave NE, Seattle, WA 98105, United States. Or visit them virtually, at https://www.burkemuseum.org/

Photo: Robert Bruce Horsfall - https://archive.org/details/ahistorylandmam00scotgoog, Public Domain, https://commons.wikimedia.org/w/index.php?curid=12805514

Reference: Prothero, Donald R. (2005). The Evolution of North American Rhinoceroses. Cambridge University Press. p. 228. ISBN 9780521832403.

Reference: O. C. Marsh. 1875. Notice of new Tertiary mammals, IV. American Journal of Science 9(51):239-250

Lincoln, Roosevelt and Recovery from The Great Depression

Rural Tennessee has electricity for the same reason Southeast Alaska has totem parks. In order to help the nation recover from The Great Depression, President Franklin D. Roosevelt, created a number of federal agencies to put people to work. From 1938-1942 more than 200 Tlingit and Haida men carved totem poles and cleared land for the Civilian Conservation Corps in an effort to create “totem parks” the federal government hoped would draw travelers to Alaska.

This odd intersection of federal relief, Alaska Native art and marketing is the subject of Emily L. Moore’s book “Proud Raven, Panting Wolf: Carving Alaska’s New Deal Totem Parks.”

This effort to bring poles out of abandoned villages includes the Lincoln Pole being moved to Saxman Totem Park by the Civilian Conservation Corps (CCC), who established the Saxman Totem Park in 1938.  

The top carving on the Lincoln Pole bears a great likeness of Abraham Lincoln. According to the teachings of many Tlingit elders, this carving was meant to represent the first white man seen in Tlingit territory in the 18th century.  

A century later, in the 1880s, one of my ancestors from the Gaanax.ádi Raven clan of the Tongass Tlingit commissioned the pole to commemorate our ancestor's pride to have seen this first white man—which has become a Gaanax.ádi crest—using a photograph of Abraham Lincoln as the model. 

It is important not only for these various readings of the crests but also because it claims Gaanax.ádi clan territory before the first Europeans and budding Americans came to these shores—territory that Tlingit carvers who were re-carving the pole in the 1940s were trying to assert to the U.S. government as sovereign land.

Interestingly, another pole in that same park is the Dogfish Pole, carved for Chief Ebbits Andáa, Teikweidi, Valley House. The Chief Ebbits Memorial Pole—the Dogfish Kootéeyaa Pole—was raised in 1892 in Old Tongass Village in honour of a great man, Head Chief of the Tongass and my ancestor. It was then moved, re-carved and re-painted at Saxman Totem Park in 1938 as part of Roosevelt's program—and it due to be re-carved again this year. 

It tells the story of his life and the curious way he became Ebbits as he was born Neokoots. He met and traded with some early American fur traders. One of those traders was a Mister Ebbits. The two became friends and sealed that friendship with the exchanging of names.  

If you would like to read more about that pole and others, I recommend, The Wolf and the Raven, by anthropologist Viola Garfield and architect Linn Forrest (my talented cousin), published in 1961 and still in print as I ordered a copy for a friend just this year.

Friday, August 27, 2021

ICE AGE MANATEES

Manatees do not live year-round in Texas, but these gentle sea cows are known to occasionally visit, swimming in for a summer vacation and returning to warmer waters for the winter. 

Interestingly, we have recently found fossil evidence for manatees along the Texas coast dating back to the most recent ice age. 

The discovery raises questions about whether manatees have been visiting for thousands of years, or if an ancient population of ice age manatees once called Texas home.

The findings were published in Palaeontologia Electronica by lead author Christopher Bell, a professor at the UT Jackson School of Geosciences with co-authors Sam Houston State University Natural History Collections curator William Godwin and SHSU alumna Kelsey Jenkins — now a graduate student at Yale University — and SHSU Professor Patrick Lewis.

The eight fossils described in the paper include manatee jawbones and rib fragments from the Pleistocene, the geological epoch of the last ice age. Most of the bones were collected from McFaddin Beach near Port Arthur and Caplen Beach near Galveston during the past 50 years by amateur fossil collectors who donated their finds to the SHSU collections.

The Jackson Museum of Earth History at UT holds two of the specimens. A lower jawbone fossil, which was donated to the SHSU collections by amateur collector Joe Liggio, jumpstarted the research.

Manatee jawbones have a distinct S-shaped curve that immediately caught Godwin's eye. But Godwin said he was met with scepticism when he sought other manatee fossils for comparison. He recalls reaching out to a local fossil enthusiast who told him point-blank, "there are no Pleistocene manatees in Texas."

But an examination of the fossils by Bell and Lewis proved otherwise. The bones belonged to the same species of manatee that visits the Texas coast today, Trichechus manatus. An upper jawbone donated by U.S. Rep. Brian Babin was found to belong to an extinct form of the manatee, Trichechus manatus bakerorum.

The age of the manatee fossils is based on their association with better-known ice age fossils and paleo-Indian artefacts that have been found on the same beaches.

It is assumed that the cooler ice age climate would have made Texas waters even less hospitable to manatees than they are today. But the fact that manatees were in Texas — whether as visitors or residents — raises questions about the ancient environment and ancient manatees. The Texas coast stretched much farther into the Gulf of Mexico and hosted wider river outlets during the ice age than it does today. Either the coastal climate was warmer than is generally thought, or ice age manatees were more resilient to cooler temperatures than manatees of today.

Subsurface imaging of the now flooded modern continental shelf reveals both a greater number of coastal embayments and the presence of significantly wider channels during ice age times.

If there was a population of ice age manatees in Texas, it is entirely plausible that they would have ridden out winters in these warmer river outlets similar to how they do today in Florida and Mexico.

Reference: Christopher Bell, William Godwin, Kelsey Jenkins, Patrick Lewis. First fossil manatees in Texas: Trichechus manatus bakerorum in the Pleistocene fauna from beach deposits along the Texas Coast of the Gulf of Mexico. Palaeontologia Electronica, 2020; DOI: 10.26879/1006

Sunday, August 8, 2021

CONLINOCERAS TARRANTENSE

Previously Calycoceras Tarrantense, this ammonite is now called Conlinoceras tarrantense after J.P. Conlin, a famous early 20th-century fossil collector from Texas, USA.

Ammonite expert Bill Cobban used this collection to describe many Texas Cretaceous ammonites species including this species from Tarrant County, Arlington, Texas.

He was a surveyor by training and kept incredibly detailed notes on the context of his fossils.

Conlin donated his collection to the USGS and we have learned much by studying it along with other specimens from the Lone Star State. Almost a quarter of Texas is covered by Cretaceous strata, much of it fossiliferous. If we stepped back 95 million years, the world and what we now call Texas was a very different place.

95 million years ago, during the Late Cretaceous, a shallow seaway separated North America into separate eastern and western landmasses. We have a pretty complete picture in the fossil record of the western groups of species but relatively little in comparison to their cohorts in the east.

At the time this fellow was swimming our ancient seas, he was sharing the Earth with carnivorous dinosaurs, duck-billed dinosaurs, mammals, crocodilians, turtles, a variety of amphibians, prehistoric bony fish, oddly prolific sea cucumbers, various invertebrates and plants. Many of these sites are just being written up now and contain new species just being discovered.

During the Late Cretaceous Period, a shallow seaway separated North America into separate eastern and western landmasses. The Woodbine Formation in Texas preserves a rare fossil record of this time for the east, but many of these fossils are isolated and incomplete, making interpretations more difficult. Preliminary excavations at the Arlington Archosaur Site (AAS) are providing hints at a more complete ecosystem, preserving similar patterns of change to what we see in the west.

The Arlington Archosaur site contains an extraordinary diversity, abundance, and quality of fossil material, preserving one of the most complete terrestrial ecosystems known for this time period and area.

These outcrops and the fossils they contain have a lot to tell us about Late Cretaceous life in the east. Over 2200 individual specimens have been found belonging to numerous groups including carnivorous dinosaurs, duck-billed dinosaurs, crocodilians, turtles, mammals, amphibians, sharks, bony fish, invertebrates, and plants.

Many of the fossils found here represent brand new species and studying these fossils will help to establish the geographic and environmental forces that shaped Cretaceous ecosystems in North America by providing a necessary comparison to the fossil record of the west.