2024 Excavation Campaign Report from the Atapuerca Sites 24th July
Among the fossils found during the 2024 excavation campaign, significant remains of Homo antecessor stand out. Specifically, these include fragments of a skull, a jaw fragment, two pieces of a mandible, and an incisor tooth. The dental piece is of particular interest as it has been confirmed to belong to an unknown adult individual, most likely a female aged around 25 years.
Atapuerca Research Team
On 18th June, the 46th excavation campaign began in the Atapuerca mountain range, led by Juan Luis Arsuaga, José María Bermúdez de Castro, and Eudald Carbonell. Over the course of the following six weeks, more than 300 researchers participated in excavating the following sites: Sima del Elefante, Galería, TD4 and TD6 levels of the Gran Dolina, Penal, Cueva Fantasma— all located in the Trinchera del Ferrocarril; Cueva de El Mirador; the open-air site Castrillo Base Aymerich; and in the Cueva
Mayor sites: Portalón, Sima de los Huesos, Ciclopes, and Galería de las Estatuas. Excavations were also carried out in the sediment washing by the Arlanzón River near Ibeas de Juarros (Burgos).
Since 1978, the Atapuerca Research Team (EIA) has been working and researching at these sites without interruption. As in previous years, the team stayed at the Residencia Gil de Siloé in Burgos, thanks to the collaboration of the Junta de Castilla y León.
This year, participants in the excavations primarily come from research centres involved in the Atapuerca Project, including the National Research Centre on Human Evolution of Burgos (CENIEH), University of Burgos (UBU), Rovira i Virgili University (URV), Catalan Institute of Human Paleoecology and Social Evolution (IPHES-CERCA), Mixed Centre of the Complutense University of Madrid – Carlos III Health Institute of Human Evolution and Behaviour (UCM - ISCIII), University of Alcalá de Henares
(UAH), University of Zaragoza (UNIZAR), University of the Basque Country (UPV), and Isabel I University (UI). Notably, several students from University College London and the National Museum of Georgia (Republic of Georgia) took part, thanks to agreements signed by the Atapuerca Foundation with these institutions.
Following previous years' practices, the Atapuerca Foundation and the Atapuerca Research Team have worked together on aspects related to safety and administrative and documentary organisation. During the campaign, most members of the Atapuerca Foundation focused on organising, logistics, and communication tasks, as well as socialising activities related to the excavations.
Below are the characteristics of the different sites being excavated during this campaign, along with the objectives set for each of them. The following outlines the most notable discoveries made during this
campaign at each of the sites worked on:
Sites of the Trinchera del Ferrocarril
Sima del Elefante
The results of the excavation at Sima del Elefante have been positive, with the objectives set at the beginning of the campaign being successfully achieved. The excavation of the clay layer in the TE7 level, where the human remains called “Pink” were found in 2022, as well as stone tools discovered in 2023, was completed. This year, a large herbivore rib was recovered from this layer, showing cut marks associated with the butchering actions of hominins who inhabited the area between 1.2 and 1.4 million years ago. Additionally, a small quartz flake was found in the TE7 level, which will help to understand how these hominins lived. Furthermore, the relationship between the TE7 level in two excavation sectors was confirmed, and it is now the largest excavated surface area at Sima del Elefante. Other remains found in these sediments include those of beavers, rhinoceroses, deer, and turtles.
Caption: Susana Santamaría | Atapuerca Foundation
During this campaign, excavation has resumed in an area of the site to locate the base of the sedimentary sequence of Sima del Elefante.
Galería
This year's campaign at Galería focused on Subunit GIIb, dated to approximately 300,000 years ago. From this point onwards, excavation enters a new phase, reaching the richest levels of Galería. Over the weeks, a total of 500 animal remains and more than 30 lithic tools have
been recovered. The faunal remains include axial and cranial bones from deer, horses, and bison, predominantly from young individuals. The lithic industry reflects the use of a wide variety of raw materials, including Neogene flint, quartzite, sandstone, and quartz arenite. Some materials were used as cores to produce flakes, while others were shaped into small tools such as scrapers and denticulates. This campaign reinforces the idea that pre-Neanderthal societies used Galería expediently as a resource-gathering site, making it a key location in the Sierra de Atapuerca.
Caption: Susana Santamaría | Atapuerca Foundation
Gran Dolina (TD6)
The 2024 campaign at the Gran Dolina site marked the highly anticipated return to level TD6, exactly 30 years after its first excavation. The campaign, carried out in July, was coordinated by a team of researchers from IPHES (Tarragona).
The previous campaign ended with the exposure of the roof of the unit containing the renowned Aurora Stratum. During two earlier excavation phases (1994–1997 and 2003–2011), the remains of an 850,000-year-old campsite were uncovered here. Alongside numerous remains of deer,
horses, bovids, and other animals, as well as a collection of stone tools used and abandoned at the site, approximately 180 human fossils were discovered. The study of these fossils documented the oldest known evidence of cannibalism and revealed a combination of anatomical traits that led to the 1997 proposal of a new species, Homo antecessor.
This year’s campaign successfully exposed the roof of unit TD6 (known as TD6.1), where an accumulation of hyaena coprolites (fossilised faeces) previously described in other areas was found to extend across a surface of nearly 40 m². This exceptional Pleistocene latrine not only documents the activity of scavengers but also confirms that the underlying layer, the famous TD6.2 level rich in archaeological and palaeoanthropological records, is well-preserved across a large area.
Caption: Susana Santamaría | Atapuerca Foundation
Importantly, in contact with the coprolite layer and amidst animal bones and some stone tools, the first Homo antecessor fossils of this campaign have emerged. These include several cranial fragments, a maxillary fragment, two mandibular fragments, an incisor, rib and vertebral fragments, and a small wrist bone. The dental piece has garnered significant interest, as initial observations indicate the presence of an adult individual previously unidentified within the assemblage, likely a 25-year-old female.
The findings confirm the excellent preservation of the TD6 unit at Gran Dolina, its exceptionally rich fossil content, and promise outstanding campaigns in the coming years, which will undoubtedly place the EIA (Atapuerca Research Team) at the forefront of scientific discovery in
Europe once again.
Gran Dolina (TD3)
TD3 exists
During 2024, progress was made in excavating what was thought to be level TD4 at Gran Dolina. However, magnetostratigraphic analysis of the sediments and a reassessment of the stratigraphic sequence during the campaign confirmed that the unit under excavation is actually TD3, a level described in the 1980s and 1990s. This unit had been neglected for two
decades, as it was believed to have little significance, had been exhausted in earlier excavations, and was not evident in profiles. Now confirmed, TD3 represents the first fertile level in the Gran Dolina stratigraphic sequence, located just below the so-called TD4.2 level.
The work conducted during this campaign has helped clarify the formation history of the Gran Dolina site. The earliest episode identified was a catastrophic event detected a few years ago, during which large blocks and speleothems fell, creating a highly irregular “lunar” palaeorelief. After this event and before the cave opened to the exterior, it was submerged, as evidenced by the stony blocks covered in a stalagmitic layer with cauliflower-shaped precipitates formed in a subaquatic environment. Once the cavity opened to the exterior, animals likely fell into it as a natural trap and accumulated in large pools within the cave, forming what is now recognised as TD3. The cave later continued to fill with external deposits, block and gravel flows, fauna, and some lithic artefacts in what was previously excavated as TD4.
Caption: Susana Santamaría | Atapuerca Foundation
At TD3, remains of large mammals that inhabited the Sierra de Atapuerca nearly a million years ago have been recovered, showcasing the region's remarkable biodiversity at the time. Horses, rhinoceroses, bison, and various types of cervids have been found, including a giant deer species, Eucladoceros gigans. Many of these remains are semi-articulated, indicating the in-situ decomposition of animals that fell accidentally. Also recovered were remains of carnivores, such as small felines, canids, and bears. The latter likely accessed the cave through secondary galleries during hibernation periods and perished inside. The presence of beavers confirms that this species was present throughout the history and prehistory of Atapuerca.
Penal
The 2024 campaign at the Penal site has been particularly successful, with the discovery of around twenty lithic artefacts in its upper stratigraphic levels. This site, identified during a survey in the 1990s and systematically reopened last year, is interpreted as part of the sedimentary infill of the Gran Dolina site. This connection was likely severed when the railway trench was constructed in the late 19th century.
The working hypothesis was that the sediments excavated at Penal were linked to the lower levels of Gran Dolina. This hypothesis has been further supported by this year’s results. The analysis of microfauna recovered from sediments washed in the Arlanzón River reveals an assemblage typical of the Lower Pleistocene. Alongside the emblematic Mimomys savini, this year’s standout finding is the identification of Dolinasorex glyphodon, an extinct species of venomous shrew with large size and red teeth. Previously, this species had only been identified in levels TD4, TD5, and TD6 of Gran Dolina. Samples have been taken for dating Penal using
Electron Paramagnetic Resonance at the CENIEH laboratories to refine its chronology. Additionally, geochemical and mineralogical sediment analyses have been conducted to compare and potentially correlate them with Gran Dolina’s levels.
During the past six weeks, stratigraphic analysis has been refined and updated. The extension of levels TP6–TP8, initiated in 2023, continued, and for the first time, excavation began on the upper stratigraphic levels, TP1 and TP2. These levels are challenging to access due to their
proximity to the vertical face of the Trinchera del Ferrocarril. Despite this, within a small area of only about four square metres in TP1 and TP2, a variety of lithic tools made from quartz, quartzite, flint, sandstone, and limestone have been found, including cores and knapping debris. Both the typological analysis of the tools and the wide variety of materials used for their manufacture resemble Homo antecessor’s toolkit, strengthening the possibility that TD6 has been found on the other side of the Trinchera del Ferrocarril.
Cueva Fantasma
Excavation work at Cueva Fantasma this year has focused on two distinct sectors: the cave’s entrance (CF), which documents Neanderthal occupation levels, and the inner part, known as Sala Fantasma (SF), where hyaena activity levels are found.
At the cave entrance, work was conducted on level CF26A, CF25 was completed, and excavation began on CF24. In the adjacent northern alcove of Cueva Fantasma, level CF26A continued to be excavated. This level, approximately 70,000–100,000 years old, yielded a significant collection of retouched scrapers and points, suggesting this was the primary area of Neanderthal activity in the cave. Lithic tools and bone remains confirm Neanderthal presence, though their visits to this area were sporadic.
Level CF25 revealed a smaller collection of lithic tools, such as flint, sandstone, and quartzite flakes, showing the development of the Levallois knapping technique. This level stands out for the accumulation of bones, with a higher degree of fracturing mainly caused by Neanderthals and hyenas. Evidence of human activity can be seen on these bones, such as breakages made to extract bone marrow. Other bones show signs of being processed and regurgitated by hyenas. After the discovery of a Neanderthal parietal bone in another part of the cave (the Phantom Chamber) eight years ago, this season a small circular fragment of a Neanderthal skull bone has been recovered.
In the other, larger area of the site, the Phantom Chamber, work has focused on sublevel SF30A. This level contains a significant accumulation of horse and deer remains, which show evidence of having been consumed, gnawed, and heavily altered by hyenas (indicating it was a
hyena den). Bones of other animals, including hyenas, lions, reindeer, bears, dogs, marmots, and bovids, have also been found. This surface is the most recent of the three, with an approximate age of around 50,000 years.
Lastly, at the lower section of CF, a survey has been initiated to document the lower part of the sequence. Levels CF23, CF22, CF21, and CF20 have been delineated, and the base of level CF20 and the top of CF19 have been excavated. Levels CF20–19 are notable for the presence of numerous hyena coprolites and remains of herbivores and carnivores, with a particular emphasis on the presence of Pachycrocuta remains. This species of hyena had not previously been documented at sites in the Sierra de Atapuerca. This discovery represents a biozone older than the base of Gran Dolina, with an age exceeding one million years, corresponding to level CF19 from the Early Pleistocene.
Cueva del Mirador
This campaign involved three weeks of excavation at El Mirador Cave with a slightly larger team than in previous years. Work focused on deepening the trenches opened on both sides of the cavity. Excavations uncovered levels from the Early Neolithic, dating back around 7,000 years. These layers are rich in animal remains, predominantly domestic species, and material culture, including ceramics with boquique decoration, as well as lithic and bone tools. A systematic sampling campaign was conducted to enable archaeobotanical, archaeomagnetic, and analytical chemistry studies, aimed at obtaining high-resolution data on the first pastoral and agricultural communities of the Iberian Peninsula's interior.
A notable discovery was the presence of rock art, both on the cave walls, where remnants of paintings were found, and within the Early Neolithic sediments. Among these, a 40 x 30 x 20 cm block covered in red pigment was discovered, alongside items such as a flint core with red markings and the base of a vessel adorned with a magnificent soliform (sun-like representation) also showing traces of red pigment.
Cueva Mayor.
El Portalón
Since 2014, excavations at El Portalón of Cueva Mayor have focused on two distinct areas: one associated with the Bronze Age and the other with the Early Neolithic.
In the Neolithic levels, dated to approximately 7,300 years ago, an activity area has been identified with numerous fire pits or hearths likely used for cooking or heat-treating flint for knapping. The animals consumed include both domestic species (such as cattle and sheep) and wild species, particularly horses, indicating a mixed exploitation of animal resources (animal husbandry and hunting). Bone tools such as awls and needles, decorative items like shell beads, and numerous ceramic fragments, some finely decorated, were also recovered. Additionally, a large number of stone tools were found, including small flint blades, hammerstones, grinding stones, and polished axes.
From the Bronze Age material, dating back about 3,000 years, excavations have revealed a layer rich in archaeological remains, with numerous hearths and a significant quantity of bone fragments and ceramics, including both plain and finely decorated pieces. The lithic industry is represented by abundant flint, quartzite, and sandstone fragments. Domestic animals, such as sheep, goats, pigs, and some horses, are represented, alongside wild fauna, primarily deer and roe deer.
The abundance of remains in both levels slows down the excavation but demonstrates the intensity with which human groups settled in this location over millennia.
Sima de los Huesos / Cyclops Chamber
The Sima de los Huesos (SH) site is located at the bottom of a deep shaft in one of the galleries of the Cueva Mayor, about 600 meters from the current entrance. This site, approximately 430,000 years old, is the place in the world that has yielded the greatest number of fossils from the Homo genus. Since systematic excavations began in 1984, around 7,000 human fossils have been recovered, representing all regions of the skeleton and belonging to at least 28 individuals of both sexes and various ages at death.
The two main objectives of the 2024 excavation campaign focused on two excavation points:
1) In the Cyclops Chamber, specifically in the area known as the Sala de las Oseras. This chamber is located near the vertical of the Sima de los Huesos, 9 meters above it. The excavation of the Sala de las Oseras was expanded to study the taxonomy of the bears found here, the origin of the deposit, and its relationship with the Sima de los Huesos. Different samples for ESR and OSL dating of the deposit were also collected.
2) In the Sima de los Huesos, excavation continued in the southern part of the site. In this area, the human fossil layer is located below the layer containing bear fossils. In addition to the excavation, new geological and sedimentary samples were taken to improve the dating of
the human fossils from the Sima de los Huesos. In this context, the results of the 2024 campaign can be considered excellent, as they have provided a better understanding of the relationship
between human fossils and the sedimentary deposit, as well as new sediment samples that will be analysed for new datings, enabling a clearer understanding of the age of the fossils, both human and bear. The progressive improvement in analysis techniques and dating
methodologies is providing increasingly precise ages, and these advanced geochronological techniques will be applied in the Sima de los Huesos.
Furthermore, some fragments of human and bear fossils have been recovered in the southern area of the Sima de los Huesos and bear fossils in the Sala de las Oseras. In these areas, the human fossils are in a very fragile condition and are difficult to extract. Studies to be carried out after the excavation campaign will help determine whether these fragments match the fossils found in previous campaigns. The discovery of these fragments confirms the widespread presence of human remains throughout the Sima de los Huesos, below the bear layer, and suggests that significant discoveries of human fossils in SH will continue over many future campaigns.