Camille Arambourg was born in Paris on February 3, 1885. He first became interested in the earth sciences and biology at a young age. In 1903, having completed two baccalaureates, Arambourg began working towards a career in agricultural research. His interest in agriculture was initially driven by the exigencies of vineyards his family had established in the Sahel of Oran, a region in northern Algeria. Arambourg had been tasked with improving the irrigation system used at the properties.
The subsoil of the geological formation which lay beneath the Arambourg vineyards dates from the end of the Miocene (23–5.33 million years ago (mya)) and the beginning of the Pliocene (5.3–2.58 mya) epochs. The formation, an ancient seabed, was first described by Auguste Pomel in 1858, and was important because it marked the regional transition between the Miocene and Pliocene. Pomel named it the Sahélien. A large number of fossil vertebrates that had been preserved in the subsoil were regularly brought to the surface by agricultural activities. Arambourg began collecting and documenting these fossils while working on the irrigation system at his family’s vineyards.
Situated on the outskirts of Algiers, the suburb of El Harrach has been home to the Ecole supérieure agronomique d’Alger, formerly the Institut national agronomique, since 1905. Located just a few kilometers away is the University of Algeria. The close proximity of these institutions allowed Arambourg to pursue his twin ambitions as an agronomic engineer and a budding paleontologist. The University’s Ecole des sciences housed an impressive collection of vertebrate fossils and studies of comparative anatomy gathered by Pomel during the nineteenth century. From these collections and the counsel of the school’s professors Arambourg was able to expand both his knowledge of paleontology and zoology.
In 1914, Arambourg was mobilized into L’armée d’Orient, serving first in the Dardanelles, and then in the Balkans. Stationed for a time in a mountainous area to the north of Salonika, he was able to continue his paleontological activities. Arambourg gathered an impressive collection of vertebrate fossils in terrain formed from lacustrine deposits roughly the same age as the marine deposits in the Sahel of Oran. Upon his return to Algeria, he was appointed a professor of Geology, first at the Institut agricole d’Alger (1920–30) in El Harrach, and then, after returning to Paris in 1930, at the Institut national agronomique (1930–36).
In 1933, Arambourg was elected a correspondent of the Muséum national d’Histoire naturelle (MNHN). Three years later he succeeded Marcellin Boule, who had been his maître at the museum, as the chair of paleontology. By this time, Arambourg had already compiled a sizable body of work for the MNHN. Among his most notable contributions were studies on the vertebrates of the Sahélien, the Pliocene mammals of the Constantinian plateaus, the fish deposits found in the Yonne Lias, the cretaceous schists of the Rharb, the Beni Segoual human ossuary in Bedjaia, and the vertebrate deposits of East Africa, especially those located in Ethiopia’s Omo Valley.1
Algeria before Arambourg
Long before Arambourg began exploring his family’s properties in Oran during the early twentieth century, the region had already been the subject of many zoological expeditions. A large number of fossils had been gathered from a diverse selection of sites dating from the Tertiary (65–2.58 mya) and Quaternary (2.58–0.012 mya) periods. As early as 1830, prehistoric research, first conducted by military engineers and later by geologists, had confirmed the existence of numerous fossil caves and open-air sites.
Sites along the Algerian coastline, due to their proximity to urban centers, were the first to be investigated. In Oran, the first observations of vertebrate fossils, and fish in particular, were made by Claude Antoine Rozet in 1831 and Georges Louis Duvernoy in 1837. Between 1861 and 1881, a coastal area between the Bouzarea and Chenoua massifs to the west of Algiers was explored in great detail by Alexandre Bourjot.2
Working in the continental formations of Constantine in the northeast of the country, Philippe Thomas found many new taxa, Equidae and large Bovidae among them, along with fish, crocodiles, and phosphate deposits.3 Tertiary vertebrates such as mastodons, elephants and African antelopes were also unearthed by Paul Gervais. In 1867, a military officer, General Louis Faidherbe, made the first excavations at Djebel-Thaya. The late Quaternary deposits at Djebel-Thaya yielded numerous finds, including bears and gazelles, which were subsequently studied by Jules René Bourguignat.
But it was the work of Pomel, at the end of the nineteenth century, that marked a decisive turning point in the development of Algerian paleontology. Between 1893 and 1898, he published no less than a dozen Monographie sur les vertébrés fossiles de l’Algérie. These included the first descriptions of many mammals, such as Cervidae, Suidae, antelopes, Equidae, and carnivora.4 Some of the specimens were extracted from the sand pits of Ternifine near Mascara that Pomel had discovered in the northwest of the country.5 Many years later, it was at this site that Arambourg would discover the oldest human fossils ever found in North Africa. Between 1910 and 1935, another key figure in the development of Algerian geology and paleontology, Léonce Joleaud, published a wide-ranging series of surveys entitled Etudes de Géographie zoologique sur la Berbérie.6 Building on the work of Pomel and Joleaud, Arambourg was instrumental in creating a rich and detailed documentary record of the country’s fauna.
From Marine Vertebrates to Mammals
Between 1912 and 1927, Arambourg collected a wide variety of fish fossils from the Chelif valley in the Sahel of Oran. These species were the subject of a formidable monograph published in 1927. Les poissons fossiles d’Oran (Fish Fossils of Oran) is 295 pages long and contains descriptions of 1,300 specimens, along with 48 figures, and an atlas accompanied by 46 plates.7 In addition to detailing the specimens, the book also offers detailed descriptions of their comparative anatomy, phylogeny, and the physiology of their organs.
The Sahélien, as defined by Pomel, is a term that has long since disappeared from the stratigraphic lexicon. The marine fauna preserved in its layers, namely fish and mollusks, are comprised of extinct forms from the Miocene along with evolved forms from the Pliocene and subsequent epochs.8 Arambourg sought to place this ancient seabed within the Algerian stratigraphic classification by seeking geological correlations in the gypsum and tripoli formations of Sicily and mainland Italy. The ichthyological fauna in these regions was similar to that found in the thick gypsum layers and tripoli deposits of the Sahélien in Dahra.
Arambourg’s investigations of the fauna from western Algeria yielded ninety-one species, including forty-two families and sixty-seven genera.9 His discovery of certain extant fossil forms marked their first appearance in the literature. Seventy percent of the Sahélien species, according to his studies, had Mediterranean affinities and eighty percent of the current genera found are still represented in the region. Phylogenetic and zoogeographic comparisons showed that Sahélien fauna was Miocene, but had some similarities to that of the Oligocene (33.9–23.03 mya) epoch. From these discoveries, new interpretations became possible. The fish of the Oran had long been thought to have originated in both marine and freshwater environments. Arambourg was now able to posit an exclusively marine origin. The Sahélien forms were similar to current marine species, such as the Alosa, the Syngnathus, and the soles. The mixing of coastal and deep-sea species was, according to Arambourg, due to the narrowness of the Sahélien sound.10
Arambourg’s first observations of mammals were made in 1927, when he began exploring a subrange of the Djurdjura Mountains in the Kabylie region of northern Algeria. He discovered a Pleistocene deposit that yielded the bones of a horned sheep (Ammotragus lervia) and the remains of a bear similar to the European brown bear (Ursus arctos). Studies of these discoveries were later published in the Bulletin de la Société d’histoire naturelle de l’Afrique du nord. These studies are significant because they contain the first notable differences in interpretation between Arambourg and his predecessor, Pomel.11 For the first time it was a paleontological perspective that provided an interpretation for the processions of mammalian fauna found in North Africa during the Quaternary period.
Arambourg described the mammalian forms he found in Algeria, and by extension those of North Africa as a whole, as present-day fauna, in the sense that modern species are still represented in the current bestiary. A mixture of forms with both tropical and paleo-arctic characteristics was emblematic of the zoogeographical domains of Eurasia, the Mediterranean, North Africa, and the Near East. At the beginning of the Pleistocene, the predominant forms were, for the most part, extinct species, or species that had emigrated from beyond the Sahara. Progressive changes to these faunas that occurred during the Quaternary period could, according to Arambourg, be attributed to important climatic changes.
This new paleontological and zoogeographic vision overturned the nineteenth-century ideas championed by Pomel, who was one of the few practitioners in Algeria influenced by the work of Georges Cuvier on the fixity of species. For Pomel, the species of the Tertiary and Quaternary periods were all extinct forms—none represented a living species. As it turned out, Pomel’s taxa could be identified either with fossil forms found in Eurasia, or with others still living today in Africa. Boule had demonstrated in 1899 that many of Pomel’s Algerian taxa were in need of reinterpretation, and Arambourg was one of Boule’s disciples.
In January 1928, during an expedition in the northeastern province of Constantine, Arambourg came across a rock shelter overlooking the Gulf of Béjaïa, in the Babor Range. This ancient marine grotto, thirty meters across and known as Afalou Bou Rhummel (Cave of the Sands) by the local inhabitants, would become one of the most important sites in Algerian prehistory.12 Under Arambourg’s direction, excavations conducted between 1928 and 1930 revealed a burial site from the Upper Paleolithic (50–10 kya) era. Dozens of individuals of varying ages were found, along with Iberomaurusian stone artefacts, and the remains of large mammals and marine invertebrates.
Arambourg described the cave as just one among a series of sites, each with a similar prehistorical chronology and each containing archaeological material comparable to the finds associated with Aurignacian–Magdalenian cultures in France. Additional sites were discovered a few years later at the Tamar Hat and Madeleine (Taza 1) caves. These had been occupied by the same Iberomaurusian peoples that lived along the Algerian coastline. The stratigraphy of the sites was also similar. In each case, base deposits were aligned with shifts in sea levels.13
From further explorations of the coastal regions surrounding Algiers, Arambourg would eventually be able to demonstrate the biostratigraphic links between mammalian fauna and their chronological context. The bone cave he discovered in 1931 at a quarry near Aïn Bénian provided crucial evidence, along with a second bone cave near Algiers that he found the following year.14 This cave yielded a rich variety of well-preserved fauna. A fossilized Lycaon was described for the first time by Arambourg, as well as the first known skull of Megaceroides algericus, a close relative of the Eurasian giant deer.15
An anthropological study of the human populations from these sites revealed a distinct morphogenetic and social identity from their shared ethnocultural and environmental characteristics, such as alveolodental mutilation and hunting practices.16 With the exception of the avulsion of the upper incisors, the facial morphology is not dissimilar from that of the Cro-Magnons. These findings led some anthropologists of the time, such as Henri Vallois, to speculate that there had been a migration from Les Eyzies in the Dordogne to the Mediterranean coasts of northwest Africa. Theories that postulate migration in the opposite direction have been favored since the 1970s.
Arambourg’s Major Sites
Arambourg was involved with excavations at a series of important new sites in Oran and Constantine from the mid-1930s until the 1950s. It was in the Hautes Plaines (High Plains) region of the Atlas Mountains that Arambourg concentrated most of his efforts. He had at his disposal a geological study of the Sétif and Hodna plateaus that had been carried out by Justin Savornin in 1920. These continental formations had long attracted geologists and paleontologists, and the area surrounding the city of El Eulma had yielded vertebrate fauna long before Arambourg’s first excavations.17
The sites at Aïn Boucherit and Aïn Hanech lie roughly nine kilometers northwest of El Eulma. Aïn Boucherit is situated at a height of 945 meters on the left bank of the Oued Boucherit and dates from the Lower Villafranchian period at the end of the Pliocene. Aïn Hanech is situated on the right bank at a height of 952 meters and dates from the Upper Villafranchian.18 Under Arambourg’s direction, excavations began during the autumn of 1948 and continued in 1949.19 The vertebrates found at Aïn Boucherit included mastodons (Anancus osiris), elephants (Elephas africanavus), zebras (Equus numidicus), three-toed Equids (Stylohipparion lybicum), a Giraffid (Libytherium maurusium), a great Bovid, gazelles (Gazella setifensis), antelopes, rodents, terrestrial and aquatic Chelonians, and an ostrich. From the Aïn Hanech site Arambourg harvested the richest selection of Lower Pleistocene vertebrate fauna ever found in the Maghreb. Among the finds were extant species from the Lower Villafranchian, but, more importantly, a range of new species that characterized the Upper period. These included Elephantids (Elephas moghrebiensis, renamed Mammuthus), Equids (Equus tabeti), rhinoceroses, Ovicaprins (Numidocapra crassicornis), amphibious hippopotami, Giraffids, swines with the characteristics of the great warthog, gazelles (Gazella pomeli), antelopes, and carnivores such as the Canidae and hyenas.
Another major site, Ternifine, had originally been discovered by Pomel in 1870. Quarrying revealed a large number of fossilized bones. The specimens were savannah fauna with tropical characteristics, and included a new species of elephant (Elephas atlantica, or Loxodonta atlantica), rhinoceroses, an Equid with zebralike characteristics and similarities to the South African quagga (Equus mauritanicus), Camelids (Camelus thomasi), giraffes, and antelopes of varying sizes. Arambourg first visited the site in 1931, but was unable to begin working there until 1954.20 Three excavation campaigns between 1954 and 1956 revealed evidence of hunting practices and large-scale stone-working activities, including several hundred pieces of quartzite, sandstone, limestone, and flint.21
But it was the discovery of human remains that greatly enhanced the importance and significance of the site. Arambourg’s first campaign yielded two mandibles, one belonging to a man, the other to a woman. Their morphological and biometric characteristics had some similarities to the Pithecanthropes and Sinananthropes of Asia, but they also possessed features unique to Algerian specimens. Arambourg named them Atlanthropus mauritanicus. A third mandible and several teeth were unearthed during the subsequent excavations.
Another of the new sites excavated around this time represented a fortuitous discovery. In the 1950s, geologists working near the Bou Hanifia dam found fossils in the Miocene layers of the Oued El Hammam valley. These continental-marine formations, once dated to the Oligocene, are concentrated in the southwest of the Beni-Chougrane massif. Arambourg’s excavation yielded a dozen species corresponding to the classic Pontian fauna of Eurasia.22
Arambourg and Evolution
Prior to the 1960s, the most influential figures in the French scientific community and the country’s most prestigious institutions, such as the MNHN, the Académie des Sciences, the Collège de France, and the University of the Sciences of the Sorbonne, were predominantly neo-Lamarckian in outlook.23 Some of the leading figures, such as Pierre-Paul Grassé, Jean Piveteau, and Pierre Teilhard de Chardin, were also deeply indebted to finalism. After his nomination to the chair of paleontology at the MNHN in 1936, Arambourg encountered many of these figures and embraced some of their ideas. On the other hand, little is known about the views regarding macroevolution that were held by Arambourg’s contemporaries working in the colonial territories of North Africa. In the nineteenth century, their predecessors had included geologists and naturalists, such as Pomel and Joleaud, whose interpretations of extinctions were influenced, at least in part, by the doctrine of the fixity of species.
What then were Arambourg’s views regarding the evolution of vertebrates, both animal and human?
For Arambourg, it was the environment that transformed species in the course of evolution. Early in his career, he gravitated towards Lamarckism. In his descriptions of fossil forms, he noted with curiosity the influence of philosophies that were often in opposition. “In the last century,” Arambourg remarked, “the influence of fixism and the global revolutions of the Cuvier school would lead us to consider different geological stages as almost necessarily distinct.” He continued,
[M]ore recently, mutationism has led to breaking up of certain natural, yet remarkably homogeneous, groups into a multitude of forms and branches theoretically independent of each other, which is, in a roundabout way, a return to the creationism of [Alcide] d’Orbigny.
At the same time, he was opposed to the “influence of Lamarckian or Darwinian ideas on the gradual continuity of evolution, which leads to the same errors.”24
Throughout his career, Arambourg sought to determine the Eurasian or African origins of species and their distribution. To explain the geological and paleontological gaps that he observed, Arambourg suggested that evolutionary phenomena were irregular.
[W]aves of fauna always accompany major geodynamic phenomena: changes in the distribution of seas and continents, marine transgressions and regressions, orogenic paroxysms, periods of calm and of organic stability correspond, on the other hand, to periods of calm and geographic stability.
The environment, in Arambourg’s view, guides animal adaptation in a uniform direction, slowly for long periods, but at other times accelerated in a way that leads to the appearance of new types.
Arambourg’s descriptions of sudden biological disequilibria were tinged, at least initially, with Lamarckian transformism: “Among all the explanatory theories that have been proposed, it is still the Lamarckian idea that seems to best account for the paradoxical pace of evolution.”25 When considering the gaps or discontinuities in the ichthyological history of the seas, he remarked, “Thus the Liasic epoch marks a profound transformation of European fauna.”26 Arambourg notes still another discontinuity:
Until the Middle Cretaceous period, the composition of European fauna retains the same characteristics, but during the Cenomanian age, a new and profound transformation abruptly intervenes and brings about the abrupt appearance of Teleostos physostomes.27
The famous conference that took place in Paris during April 1947 on the topic of “Paléontologie et transformisme” did not provoke Arambourg to reevaluate his ideas. On the one hand, there were French paleontologists, anatomists, naturalists and zoologists such as Arambourg, Vallois, Jean Viret, Piveteau, Teilhard, Lucien Cuénot, and Grassé, who adopted traditionally Lamarckian positions. Some anatomists and geneticists, such as Georges Teissier and Marcel Prenant, sided with the neo-Darwinists. On the other hand, there were English and American adherents to the synthetic theory of evolution, such as J. B. S. Haldane, David Watson, and George Simpson. The meeting was a disappointment and three years later Piveteau organized another. Once again, Arambourg rejected Darwinian ideas, even though these ideas were gaining more and more followers, including paleontologists and anatomists.
Questions were raised by Yves Coppens about the biological disequilibriums by which Arambourg was attempting to explain human evolution. Following the announcement of the discovery of the Zinjanthrope of Olduvai in 1960, Arambourg came to interpret the sequence of evolutionary stages at the end of the Tertiary–Quaternary in terms of a series of mutations. The term mutation had, in fact, appeared in his publications about vertebrates as early as the 1950s,28 and then in his writing on the origins of man, in particular from 1956.29 But during the 1960s, in virtually all his publications addressing the origins of man Arambourg’s earlier wordings reappeared:
Today, all specialists know that in the paleontological history of living beings the apparent continuity of what we call an “evolutionary series” is only the sum of a series of discontinuous mutations, each of which corresponds to an ever closer adaptation to particular biophysical conditions and lifestyles. These mutations are probably, as suggested by Wintrebert with great pertinence, the consequence—at the level of the genetic equipment of the sexual products of individuals—of the hormonal reactions of these to the aggressions resulting from variations of the biophysical environment with which they are in temporary equilibrium.30
Arambourg was, at times, opposed to the synthetic theory of evolution, since for him the whole history of life was explained by genetic transformations. He did not accept the notion of random mutation, as stated in the synthetic theory of evolution. For him, in common with Lamarckism itself, heredity was guided by the environment. “Successive mutations,” Arambourg remarked, “correspond to organic and functional specializations increasingly tailored to particular lifestyles and whose process is irreversible.” He discussed the irreversibility of the evolutionary process in the final edition of his Genèse de l’Humanité (Genesis of Humanity), published in 1969. While taking into account the concept of orthogenetic direction, he radically changed his interpretation by stating that it is a matter of the “consequences of the constant triage, by natural selection, of mutations more and more adapted to each biotope or to each function.” Arambourg, who had once been a fervent supporter of Lamarckism, or neo-Lamarckism, had, like so many others, modified his views regarding evolution just before his death. He had not, it should be noted, endorsed the mechanism of natural selection in any of his previous publications. He may have sought in his last publication to reintegrate les archives fossiles into the mainstream.
Translated and adapted from the French by the editors.
