Pleistocene Cave Bear Footprints Discovered in Spain

Paleontologists have discovered a set of ancient bear footprints in Honseca Cave, northern Spain. Although distinguishing cave bear from brown bear tracks is complex, cave bears are considered the most likely tracemakers in Honseca.

Cave bears (Ursus spelaeus) were a very large type of bear that formed the sister lineage of living brown bears and polar bears.

These animals lived in Europe and Asia during the Pleistocene epoch and became extinct about 24,000 years ago.

They were 2.7-3.5 m (8.9-11.5 feet) long and up to 1.7 m (5.6 feet) at the shoulder, and weighed between 225 and 500 kg.

Cave bears and people likely encountered one another occasionally.

Despite their name, they didn’t actually live in caves but only used them for hibernation.

The massive grinding molars and nitrogen-isotope data from its bones indicate that cave bears were primarily herbivorous, with foliage their main dietary staple.

“Cave bear tracks are not uncommon in the soft sediments of the caves of the Iberian Peninsula and many speleologists are familiar with their presence,” said Dr. Ana Mateos from the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH).

“However, until now these fossil traces had not been the subject of systematic research.”

“In fact, to date only one study of this type was carried out in Urşilor Cave in Romania.”

Dr. Mateos and colleagues discovered a set of 16 cave bear footprints in Honseca Cave, Palencia, Spain.

The footprints were assigned to Ursichnus europaeus and represent the first record of this ichnospecies from a cave in the Iberian Peninsula.

“We carried out a scan of the surface with the footprints and its immediate surroundings with a laser scanner that creates a three-dimensional cloud of millions of points and we combined it with a model obtained by photogrammetry,” said Dr. Adrián Martinez, a technician at CENIEH.

“This model has been used to take different measurements of the footprints and compare them with those of other caves in Europe, like the Romanian cave of Urşilor.”

“In addition, processing the model has allowed us to generate images that highlight the shape of each individual footprint,” added Dr. Alfonso Benito, also of CENIEH.

“The shape of the toe impressions and the length of the claw marks, both in Urşilor and Honseca, suggest that in both cases they belong to cave bears, a species that went extinct around 28,000 years ago, rather than brown bears.”

“Unfortunately, some of the footprints were destroyed by the footsteps of amateurs who visited the interior of the cave without being careful before the scientists knew of their existence,” said CENIEH’s Dr. Jesús Rodríguez.

“Therefore, one of the goals of these types of studies is to highlight the value of these fossils and promote their preservation.”

The study was published this month in the journal Ichnos.

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J. Rodríguez et al. Cave bear tracks (Ursichnus europaeus Diedrich, 2011) from Honseca Cave, Palencia, Spain. Ichnos, published online January 9, 2025; doi: 10.1080/10420940.2024.2446153