Ecological adaptations and tracking climatic changes through time using dental wear analysis

Two studies recent published conduct us to two important conclusions:

- Dental wear reveals to be a better tool to investigate adaptations than tooth morphology, especially for the analysis of samples from Pleistocene localities. Dental wear analysis reveals changes that dental morphology does not detect.

- These studies revealed that fossils are of value in developing an understanding of the dietary breadth and ecological versatility of species that, in recent times, are rare, endangered, and occupy only a small remnant of their former ranges.



Preparation of high-resolution molds in silicone for dental wear analysis

Recreating paleodiets from fossils has often included considerable speculation. Even rigorous studies can sometimes misjudge diet due to phylogenetic constraints in the morphology. In spite of the difficulties, diet aids in interpretation of the habitat and ecological interactions. The indirect evidence from herbivores is sometimes the only indication of plant types in the area, because the fluctuation of herbivore abundance yields insight to the climatic transitions of an area.

The diet of fossil ungulates provides valuable information about the food resources in a given habitat and thus is a useful tool in reconstructing paleohabitats. The dietary interpretation of mammalian teeth has traditionally involved either direct (actualistic) comparison with living animals, the application of general functional principles, or - increasingly during the latest few decades - the study of the wear patterns left on teeth by food.

Using dental wear analysis (mesowear and light stereomicroscopy microwear), various species are used to reconstruct ecological adaptations and to track climatic changes through time.

Groups with a long evolutive history are interesting to analyze changes through time. The project realized on the Antilocapridae (a group endemic to North America) result from a collaboration with Gina M. Semprebon (Professor of Biology and Chair of the Science and Mathematics Department at Bay Path College, USA). All specimens available in the Frick Collection from the American Museum of Natural History (New York) were sampled. Species analyzed spanned from the early Miocene to the late Pleistocene. Results are concordant with well known trends toward increasing aridity and shifts in vegetational structure in the late Miocene–early Pliocene of North America.

Results indicate a shift toward more abrasive diets beginning in the late Miocene and Pliocene, and then a return to a less abrasive dietary regime for the duration of the Pleistocene and into the Recent. More interesting is that the antilocaprines (the more derived group, more hypsodont) apparently depended more on grass than the less advanced merycodontines, but even the earliest of the merycodontines seem to have relied more on grass as a dietary staple than the modern pronghorn. Seasonal grit encroachment on food items encountered by fossil antilocaprids coupled with a heavier reliance on grasses may provide a possible explanation for the extreme hypsodonty present in the modern pronghorn despite its mainly browsing dietary behavior.

From: Semprebon G. M., Rivals F. 2007. Was grass more prevalent in the pronghorn past? An assessment of the dietary adaptations of Miocene to recent Antilocapridae (Mammalia: Artiodactyla). Palaeogeography, Palaeoclimatology, Palaeoecology 253: 332-347.

Populations of caribou

A second study was undertaken on a large sample of modern caribou (Rangifer tarandus) from the Kaminuriak population of eastern Canada. The project is part of a collaboration with Nikos Solounias (Professor at New York College of Osteopathic Medicine and Research Associate at the American Museum of Natural History in New York). The modern sample was compared to fossil specimens from Pleistocene localities in North America (Alaska) and Western Europe (Caune de l’Arago in France and Salzgitter in Germany).

Microwear features on a bovid tooth (magnification x35)

The results show that the extant samples from eastern Canada have seasonal variation in microwear and presumably in diet. Those differences in microwear may reflect a cyclic migration of the population within a year. Rangifer samples from the three fossil localities show that diet of a brachyodont taxon can be highly abrasive, comparable to the diet of modern zebras or plains bison. More over their diet may vary across most of the dietary morphospace of ungulates, indicating an important adaptability of the individuals.

The three Pleistocene samples exhibit microwear that is different from the extant population in question. This observation implies that the recent diet of Rangifer has changed from the typical caribou diet in the past. This indicates dietary change within a species. This is important because it represents dietary evolution without changes in tooth morphology. These results are significant due to climatic deterioration and can be used to detect changes in time and trends in the future of some species as humans alter their habitats.

From: Rivals F., Solounias N. 2007. Differences in tooth microwear of populations of caribou (Rangifer tarandus, Ruminantia, Mammalia) and implications to ecology, migration, glaciations and dental evolution. Journal of Mammalian Evolution 14: 182-192.

For further information: Florent Rivals, florent.rivals@icrea.es

Bronze Age cannibalism in Atapuerca

Evidence for Bronze Age cannibalism in El Mirador Cave (Sierra de Atapuerca, Burgos, Spain), American Journal of Physical Anthropology, Volume 133, Issue 3, Date: July 2007, Pages: 899-917

Isabel Cáceres, Marina Lozano, Palmira Saladié

Área de Prehistoria de la Universidad Rovira i Virgili de Tarragona, IPHES (Institut de Paleoecologia Humana i Evolució Social), Fundación Atapuerca

During excavations of the Bronze Age levels at El Mirador Cave, a hole containing human remains was found. Taphonomic analysis revealed the existence of cutmarks, human toothmarks, cooking damage, and deliberate breakage in most of the remains recovered, suggesting a clear case of gastronomic cannibalism. The piled distribution of the remains, the uneven skeletal representation, and the chronological difference between the pit and the remains suggest that these bones were subsequently buried by a human group that inhabited into the cave later in time.

Outside Trinchera del Ferrocarril complex and Sima de los Huesos site, El Mirador Cave is located at the southern side of the Sierra de Atapuerca (Burgos, Spain). The Bronze Age remains noticed here appeared in a 6 m2 exploratory excavation. Dating based on charcoal and bone shows that MIR4 corresponds to the Middle Bronze Age. The human remains provide calibrated dates between 4400 and 4100 BP. Dates indicate that the human remains considered here would fit chronologically into the Early Bronze Age.

Dorsal vertebrae exploitation pattern (MIR4-P22-212a and 212b):

cutmarks (arrow) cross both vertebrae as a result of the same

action. Also there are toothmarks on the laminae and peeling

of the spinal process. The articular facets have completely

disappeared.

The assemblage of human remains recovered from El Mirador Cave consists of 106 specimens belonging to at least six individuals. These remains show evidence of systematical dismemberment, defleshing, and consumption. The distribution of these human remains, with skulls at the bottom and postcranial bones on cranial remains, the abundant bones breakage and the obvious presence of cutmarks, cooking damage, and possible human toothmarks, provide evidences of cannibalistic practices during recent periods of prehistory. All taphonomic alterations on these human remains are anthropogenic in origin. Most incisions indicate that these bodies were defleshed and disarticulated. Cutmarks appear in areas of muscle insertion, following patterns of processing, which are similar in all individuals. Another significant feature of the assemblage is a high degree of bone fragmentation. Analysis of the fracture outline shows a majority to have curved/V-shaped with mixed angles and smooth edges. These features suggest that the breakage occurred while bone was fresh. Human toothmarks in El Mirador Cave are always superficial and small. The size of toothmarks, the presence of peeling associated with toothmarks, crenullated edges on very fragile bones, the similarity with experimental specimens, together with the absence of other modifications, which are typical of carnivores, allow us to propose that in El Mirador Cave, human toothmarks have been identified.

These remains were subject to complex perimortem processing, though it is not possible to determine how the individuals died. The human bodies had been processed similarly to other animals. This processing pattern is similar to that observed in butchered animals from this as well other archaeological sites. There are clear similarities with other archaeological assemblages displaying evidence of nutritional cannibalism, such as published for other sites like Moula-Guercy, Gough’s Cave, Grotte des Perrats, Fontbrégoua, Las Majólicas and the cave of Malalmuerzo or Mancos.

The presence of perimortem cutmarks, human toothmarks, bone breakage, and effect of cooking strongly suggest the existence of Bronze Age gastronomic cannibalism in El Mirador Cave.

To comments icaceres@prehistoria.urv.cat

Bos evolution relationships with Acheulean tool technology

The Olduvai buffalo Pelorovis and the origin of Bos. Quaternary Research 68 (2007) 220-226 doi:10.1016/j.yqres.2007.06.002

The origin of the genus Bos is a debated issue. From ~0.5 Ma until historic times, the genus is well known in the Eurasian large mammal assemblages, where it is represented by Bos primigenius. This species has a highly derived cranial anatomy that shows important morphological differences from other Plio-Pleistocene Eurasian genera of the tribe Bovini such as Leptobos, Bison, Proamphibos-Hemibos, and Bubalus. The oldest clear evidence of Bos is the skull fragment ASB-198-1 from the middle Pleistocene (~0.6–0.8 Ma) site of Asbole (Lower Awash Valley, Ethiopia). The first appearance of Bos in Europe is at the site of Venosa-Notarchirico, Italy (~0.5–0.6 Ma). Although the origin of Bos has traditionally been connected with Leptobos and Bison, after a detailed anatomical and morphometric study we propose here a different origin, connecting the middle Pleistocene Eurasian forms of B. primigenius with the African Late Pliocene and early Pleistocene large size member of the tribe Bovini Pelorovis sensu stricto. The dispersal of the Bos lineage in Western Europe during middle Pleistocene times seems to coincide with the arrival of the Acheulean tool technology in this continent.

Bienvenido Martínez


For this analysis, we include the Eastern African Late Pliocene species Pelorovis turkanensis from eastern Africa and P. oldowayensis, recorded in the early Pleistocene of Eastern Africa and the Levantine corridor.

According to the evidence discussed above, we propose a reclassification of the Late Pliocene and early Pleistocene African members of the tribe Bovini ascribed to Pelorovis and the middle Pleistocene–Holocene African and Eurasian specimens ascribed to Bos, including all of them in the genus Bos.

Under this new interpretation, we recognize here three chronospecies: (1) Bos turkanensis for the Late Pliocene African form; (2) Bos oldowayensis for the early Pleistocene form of Africa and the Middle East; and (3) B. primigenius for the Eurasian middle Pleistocene to Holocene form.

The extant representatives of the genus Bos are common animals in human settlements, but now we can suggest that they have been part of the human ecological scenario since the beginning of the genus Homo, during the African Late Pliocene.

Please cite this article as: Martinez-Navarro, B., et al., The Olduvai buffalo Pelorovis and the origin of Bos, Quaternary Research (2007), doi:10.1016/j.yqres.2007.06.002 © 2007 University of Washington. All rights reserved.

Bienvenido Martínez-Navarro. ICREA, Area de Prehistòria-IPHES, Universitat Rovira i Virgili. Plaça Imperial Tarraco, 1. 43005 Tarragona, Spain
Juan Antonio Pérez-Claros. Departamento de Geología y Ecología (Área de Paleontología), Facultad de Ciencias, Campus Universitario de Teatinos. 29071 Málaga, Spain
Maria Rita Palombo. Department of Earth Sciences, University of Roma “La Sapienza”, and CNR Istituto di Geologia Ambientale e Geoingegneria, Piazzale Aldo Moro 5, 00185 Roma, Italy
Lorenzo Rook. Dipartimento di Scienze della Terra, Università di Firenze, via G. La Pira 4, 50121 Firenze, Italy
Paul Palmqvist. Departamento de Geología y Ecología (Área de Paleontología), Facultad de Ciencias, Campus Universitario de Teatinos. 29071 Málaga, Spain

To comments bienvenido@icrea.es

Found a human tooth dated to ca. 1.2 My in the Sima del Elefante (TE9), Atapuerca

1.2-My-old hominid premolar discovered in the level 9 of the Sima del Elefante. Picture: Jordi Mestre/IPHES.

Last Wednesday, June 27, one P4 was found in the level 9 of the Sima del Elefante, Atapuerca.

“This find occurring within TE9 is very important as it directly proves that there was human presence in the Sierra de Atapuerca at least 1.2 millions of years ago” has been assured by Eudald Carbonell, director of the IPHES and co-director of the Atapuerca Project together with José María Bermúdez de Castro (CENIEH) and Juan Luis Arsuaga (UCM–ISCIII). He has added “In previous years we had found lithic industry which guaranteed this age, but we had never found human remains in the site”.

Along the same lines Rosa Huguet, who defended her doctoral thesis dealing with human occupations in Atapuerca and Orce just few weeks ago at the URV, points out “I already defended in my thesis a hominid presence in Atapuerca 1.2 millions of years ago, but I based it on cut marks observed on faunal remains, which would have been consumed by these hominids, as well as on the documented lithic industry. The fact that this premolar has now been found is a direct evidence which demonstrates the human presence of the Sima del Elefante at that period”.

Exactly, the tooth is a P4, a very well preserved lower premolar which would be ascribed to an adult. Regarding the species to which it could belong, Carbonell has pointed out “We still do not know, but in any case it would be a species previous to Homo antecessor and the direct evidence of hominids in Western Europe would be put back 400,000 years”.

Carbonell has also stated ‘To date it, we have for the moment biostratigraphical data coming from the level where the molar has appeared; the presence of Allophaiomys lavocati indicates us an age older than 1.2 millions of years. Equally, the first palaeomagnetic tests that we have carried out show us reversed polarity’

Carbonell has remarked "We must carry out new palaeomagnetic analyses because we are thinking that the dates of this level could be even older than 1.2 millions of years. For the time being, however, the sites located in Atapuerca reinforce its importance as a key place for the study of human evolution, because at several sites (TE9, TD6, TG10, SH) and in a good stratigraphical context we have remains of different hominid species, which are respectively 1,200,000, 800,000 and 500,000 years old.

English version by Fernando Sánchez Trigueros

original version http://www.urv.cat/iphes

The pre-inscription for the Master Erasmus Mundus of Archaeology from the Quaternary and Human Evolution is open

The first phase of the pre-inscription is already open to access to the Master Erasmus Mundus of Archaeology from the Quaternary and Human Evolution that imparts the University Rovira i Virgili of Tarragona. This first deadline finishes on the 30th April.

This Master started to be imparted in the course 2004-2005, therefore, it arrives already at its fourth year. During course 2006-07 the students (fifteen) of the first promotion finish already and they will have defended their theses of master, in different calendars, and next course they are going to carry out their studies to finish with the doctorate at Tarragona, in the same research team directed by Eudald Carbonell, director of the IPHES (Catalan Institute of Human Paleoecology and Social Evolution) and codirector of the Atapuerca Project in Tarragona.

In total, from the first edition, and during the three first courses, 45 students have followed in Tarragona the classes of this official master. These students are from very diverse origin, and there is as much of the Spanish as of the foreigner, especially people part of research teams that carry out important archaeological excavations like Atapuerca (Burgos-Spain), Dmanisi (Georgia) or Argel (Algeria), among other.

Of this total there are fifteen students from Italy, Ivory Coast, Algeria, Philippines, Indonesia and Jordan that have received the classes in other places, but have come to the URV to develop their projects of research within the framework of this international master.

The Master Erasmus Mundus of Archaeology from the Quaternary and Human Evolution is based in three fundamental areas: the research in human paleo-ecology and prehistory, paleo-anthropology, geology and palaeontology of the Quaternary; the archaeology of intervention in this stage of the evolution, and the management, conservation and socialization of the archaeological patrimony.

This official qualification of the URV share goals and formative activities with the graduations in History and Geography through the objective of introducing to a specialization in archaeology.