Moving into Friesenhahn Cave requires descending a 30-foot creaky metallic ladder, by way of a slender shaft that opens right into a darkish one-room cave. Water drips sporadically from its limestone roof, and the cave ground is a combination of clay, mud and bones — a few of them tens of 1000’s of years previous.
Among the most fearsome Ice Age predators used this cave as a den, dragging prey again into the cavern, accumulating one of the crucial well-preserved fossil data in North America.
These predators included large short-faced bears, dire wolves — and most famously — the scimitar-toothed cat (Homotherium), which banded collectively to hunt younger mammoths and different weak animals.
Jennifer Hofmann, a professor at Concordia College Texas who manages the cave, identified fossils illuminated by her head lamp.
“That’s in all probability the underside of a tibia … of a mammoth. It’s huge,” she stated, pointing to a bone lodged in sediment. “(And) that’s in all probability a Homotherium leg or arm. Simply within the final 12 months, that has uncovered itself.”
Friesenhahn Cave is positioned simply 20 minutes north of downtown San Antonio. For researchers who research life in the course of the late Pleistocene, “Friesenhahn Cave is unavoidable,” stated John Moretti, a paleontologist on the College of Texas Jackson College of Geosciences.
Regardless of being internationally identified throughout the subject, most San Antonio residents have by no means heard of the cave.
To some extent, the cave’s house owners since 1998 — Concordia College Texas — have most well-liked it that means. Its entrance is positioned on 4 acres of personal land in the course of an prosperous subdivision, separated solely by a wood fence and brush. Protecting noisy neighbors away has not all the time been simple.
Concordia isn’t the primary guard of this Ice Age treasure. Lengthy earlier than the college knew the cave existed, the household that owned the land above it had its personal causes for protecting individuals away.
Previous Man Friesenhahn
Across the flip of the twentieth century, two German brothers by the final title of Friesenhahn arrived in Central Texas trying to purchase land. One in every of them, Alfred Friesenhahn, established a sprawling ranch in Bexar County, close to the city of Bulverde, property that included the doorway into an unexplored cave.
It’s unclear who first descended the mossy sinkhole that leads down into the cave. One household legend, Hofmann recounted, is that one of many Friesenhahns first explored the cavern and initially thought the massive bones that lay in it belonged to their cattle that had fallen down the vertical shaft.
The cave was formally surveyed for the primary time in 1915 by D. V. Schuchardt, a scholar on the Agricultural and Mechanical Faculty of Texas (now Texas A&M), who was employed by a analysis affiliate on the Carnegie Establishment of Washington to check the cave and convey again a “trial assortment” of fossils.
Schuchardt described the ground of the cavern — which he known as “Bone Cave” and “Bulverde Cave” — as being buried beneath 3 toes of fossil-rich sand and clay. He retrieved fossils belonging to 18 totally different animal species, about half of which had been extinct.
In 1920, Elias Howard Sellards, a geologist and paleontologist with the College of Texas, had deliberate on conducting a extra thorough excavation of the cave following Schuchardt.
However that journey by no means occurred. In actual fact, no different researchers could be allowed again into the cave for an additional three many years. The explanation why continues to be debated. What is obvious is that the proprietor of the property wouldn’t let Sellards or anybody else onto his ranch.
In accordance with retired College of Texas paleontologist Ernie Lundelius, the explanation “previous man Friesenhahn” gave for denying researchers entry to the cave was that he felt prefer it was improper to disturb bones that had been laying there untouched for therefore lengthy. Lundelius, now in his late 90s, recounted this story final 12 months throughout an interview with Texas Cache, a web based Texas historical past journal.
However there was one other clarification.
When paleontologists with the College of Texas had been in a position to conduct the primary thorough excavations of the location in 1949 and 1951, they uncovered a plethora of fossils, but additionally giant chunks of “concrete castings.”
Opinions on what these giant chunks of concrete belonged to are blended. The preliminary opinion of some researchers was that they had been rotten water troughs from the ranch that had been pushed into the cave.
Others, although, thought they resembled castings used to distill or retailer whiskey.
In accordance with Hofmann, a Friesenhahn member of the family — the nephew of Alfred Friesenhahn who grew up on the ranch — defined that his uncle was promoting alcohol to U.S. Military personnel in San Antonio throughout prohibition, which lasted from 1920 to 1933.
The idea is that he had been utilizing the cave to cover or distill the contraband, and that this was the true cause he didn’t need anybody close to the cave for therefore a few years.
In accordance with David Barkalow, a historian at Wayland Baptist College San Antonio who wrote the entry for Friesenhahn Cave on the Texas State Historic Affiliation web site, there aren’t any written historic accounts he’s discovered corroborating the story.
Retired Concordia professor Larry Meissner, who was the cave coordinator earlier than Hofmann from 1997 to 2014, stated he was initially skeptical of the story till he heard the Friesenhahn member of the family’s story.
“After listening to the story that Dr. Hofmann was advised throughout an interview of one of many early Friesenhahn relations, I grew to become satisfied that there could also be some fact to the legend,” he stated.
A lot of the cave’s early historical past has sadly been misplaced to time, residing solely with a handful of secondhand accounts from Friesenhahn relations who couldn’t be reached for interviews.
Nature’s time capsule
Lengthy earlier than the Friesenhahns, round 15,000 to twenty,000 years in the past, ice sheets blanketed the higher half of North America, stretching as far south as Indiana. Central Texas was a dry, cool grassland with secure temperatures 12 months spherical, house to mammoths, large bears, saber- and scimitar-toothed cats and even early people.
It was what we colloquially discuss with because the Ice Age, and what scientists would extra particularly name the Late Pleistocene or Final Glacial Most.
Throughout this era, an extended ramp declined 30 toes underground into the cave, providing shelter for quite a lot of animals. In some unspecified time in the future, the doorway collapsed, sealing the cave and the bones that lay in it for an unknown time period. This protected the cave’s fossils from the wind, warmth and animals that will have degraded the fossils.
A sinkhole later fashioned above the cave, providing vertical passage right into a trove of fossils in pristine circumstances — “nature’s time capsule,” as Moretti put it.
The cave isn’t very giant, about 30 by 60 toes. Researchers needed to bend over to navigate a lot of the cave, however a number of toes of fossil-bearing materials have been faraway from the cave ground, permitting you to comfortably stand in a lot of the cave.
The cave has been such a productive fossil web site, in truth, that researchers have been in a position to make conclusions not simply in regards to the animals alone, but additionally how they interacted with one another and their setting.
“Everybody needs to seek out one other Friesenhahn Cave,” Moretti added.
The cave is finest identified for its plethora of fossils belonging to the Homotherium serum, a big scimitar-tooth cat resembling the extra generally depicted saber-toothed cat, or Smilodon.
Bones representing as many as 30 Homotherium cats had been discovered within the cave, together with full skeletons, Moretti stated. Earlier than these stays had been recovered from Friesenhahn Cave, the Ice Age cat was identified solely from tooth and disparate bones
“Fossils of these cats are uncommon in every single place, besides Friesenhahn Cave,” Moretti stated. “[Some of them] had been discovered and buried in in all probability the identical spot and place that they died in. That’s distinctive.”
Researchers imagine that over tens of 1000’s of years, the cats and different predators like bears, dire wolves and coyotes used the cave as a refuge, venturing outdoors to hunt after which dragging what remained of their prey again to the cave.
The scimitar-toothed cats particularly gave the impression to be looking juvenile mammoths, seemingly in packs, as evidenced by the massive variety of mammoth stays within the cave which can be broken in methods in line with the chew of Homotherium serum, in response to a 2021 paper printed in Present Biology.
“Homotherium might have shared some affinities with the African cheetah,” researchers wrote. “Nonetheless, Homotherium was really a cat like no different.”
The stays of camels, bison, long-nosed peccary and lots of different Ice Age animals have been pulled from the cave over time. All advised, the excavations to this point have yielded greater than 4,000 tooth and bones representing over 30 genera of Ice Age mammals, reptiles and birds.
One problem with Friesenhahn Cave has been getting a clearer image of how a lot overlap there was between the assorted animals that died within the cave. When scientists have tried to measure the age of the natural matter contained in the cave utilizing radiocarbon courting, the outcomes have been inconsistent, Moretti defined.
The speculation is that the stays gathered round 15,000 to twenty,000 years in the past, towards the top of the Pleistocene, however they is also considerably older, over 50,000 years, Moretti defined.
A not-so-well-kept secret
In 2001, then a biology undergraduate scholar at Concordia College Portland, Hofmann had the prospect to go to Friesenhahn Cave for the primary time. She and different researchers camped out in what was then distant wilderness, “simply scrub and cedar,” pitching tents and telling tales round a campfire close to the cave’s entrance, Hofmann stated.
Two years later, when she returned as a graduate scholar, the cave was basically in the course of a neighborhood, flanked on all sides by a subdivision. As improvement grew, so did rumors a couple of close by cave filled with Ice Age bones.
At present, houses are packed tightly collectively, sitting proper up towards the property line.
College officers have tried to maintain noisy neighbors away. They minimize down an indication off the street figuring out the cave and even scrubbed native on-line maps labeling the cave’s location. Inevitably although, children within the neighborhood — fueled by rumors of an city legend of a cave full of Ice Age bones — couldn’t keep away.
A couple of years in the past, when San Antonio firefighters visited the cave to determine emergency plans within the case of a hearth or flood, two firefighters who grew up within the neighborhood sheepishly admitted to Hofmann that that they had been spelunking down within the cave as children. The researchers have discovered beer cans within the cave, each fashionable ones and Lone Star beer cans with a pull-tab from the Fifties — presumably artifacts from the College of Texas researchers.
To tamp down on trespassing, Concordia constructed a heavy, locked metallic grate above the cave and put up safety cameras and no trespassing indicators. Nonetheless, safety stays a problem. Youngsters from the neighborhood broke the lock and broken the ladder years in the past.
Whereas strolling across the perimeter of the property, Hofmann paused to choose up an empty BuzzBallz container, and later discovered an space of damaged fence behind a neighbor’s house. “It is a new one,” Hofmann stated, pulling the damaged fence again in place. “Not good.”
The college has engaged with neighbors and the owners affiliation to speak the significance of preserving the cave. A couple of neighborhood volunteers assist keep the property, selecting up litter and feeding the stray cats which have commandeered the world.
There’s additionally environmental challenges, Hofmann stated. The cave’s entrance was as soon as lined in moss and ferns, however the surrounding improvement has altered the stream of water into the cave. The college bought extra property across the collapse an effort to stop extra disruption.
Concordia, a small Christian school in Austin, is an unlikely proprietor of Friesenhahn Cave. Situated two hours away from San Antonio, the faculty affords biology and environmental science levels however doesn’t have a paleontology program of its personal. Hofmann herself is a molecular biologist.
In 1998, the cave property was donated to them by the earlier property proprietor whose daughter attended Concordia. The proprietor, who most well-liked to not be named, was additionally energetic within the Missouri Synod denomination of the Lutheran Church.
The Austin college is affiliated with — however not ruled by — the denomination. In accordance with Hofmann, the house owners selected Concordia because the cave’s new steward partly as a result of they needed to spur conversations between religion leaders a couple of debated subject throughout the denomination: the age of the Earth.
Though the church’s official place on the age of the Earth is that it doesn’t have an official place, many pastors within the church settle for a Younger Earth creationist view. Younger Earth creationists imagine the Earth is 6,000 to 10,000 years previous, based mostly on a literal interpretation of the Bible’s Ebook of Genesis — which stands in distinction to the scientific consensus that the planet is 4.54 billion years previous.
Concordia taking possession of the cave has led to some difficult — however very a lot wanted — conversations between religion leaders, college and scientists, Hofmann stated.
Meissner and Hofmann have even introduced some church leaders to the cave to debate what they’ve discovered, and what it tells them in regards to the previous. They’ve additionally introduced Ok-12 college students and academics to the cave with the assistance of grant funding to show them about paleontology.
“Once we acquired the cave we assured the donor that we might have interaction with each the scientific and theological communities, being as goal as potential and letting the information take us the place it takes us,” Meissner stated. “I’ve acquired overwhelmingly constructive responses to this strategy from our constituency and the science professionals.”
Puzzle items
Concordia is now gearing as much as inform the cave’s story to a wider viewers. The college partnered with San Antonio’s Witte Museum to function Friesenhahn Collapse its just lately opened “Adventures in Texas Deep Time” exhibit. It features a mild detection and ranging scan that provides the general public a 3D view of the cave.
“Now they will actually see a three-dimensional image of what the cave appears like,” Hofmann stated. “They’ll look at a few of the specimens from the cave. They’ll type of see … the place this cave matches into the larger story of Texas historical past, which is what this exhibition on the [Witte] Museum is doing.”
Though the college is eager on making the cave’s story extra seen to most people, officers nonetheless wish to hold its location off the map as finest they will. That’s as a result of there’s much more digging and exploration to be carried out in Friesenhahn Cave.
Researchers have confirmed the existence of a slender opening in a piece of the cave ground that leads right into a bus-sized cavern, the place many fossils have seemingly washed into. And there might be many extra enclosed limestone-carved caverns within the space.
“There are caverns in all probability all underneath this, and the query is are they underneath anyone’s home?” Hofmann stated. “It could be a very good factor to know. You don’t desire a sinkhole opening up.”
Moretti has his personal record of open questions: How lengthy did the cats truly dwell within the cave? Is there one other full Homotherium skeleton ready to be uncovered? What lies behind the unique caved-in entrance?
Getting solutions means doing extra fieldwork — one thing that has fallen out of favor throughout the subject of paleontology since across the 2000s. Analysis priorities have largely shifted to utilizing new know-how to look at fossils already sitting in college and museum collections, he stated, and fieldwork is slower, costlier and sometimes doesn’t repay for a younger researcher the best way it could have previously.
Even so, a web site as vital as Friesenhahn Cave ought to be capable to entice funding. “It’s Friesenhahn Cave,” he stated. “You may get funding.”
“We’re attempting to construct the entire puzzle, however … we don’t have the field lid to know what we’re constructing towards,” Moretti stated. “We all know it’s incomplete, however we don’t actually understand how and in what means it’s incomplete.”
