Early and Middle Pleistocene of North America

A reappraisal of the Early to Middle Pleistocene Italian Bovidae

The current study focuses on the emblematic Myopus/Lemmus species complex (tribe Lemmini) in the European Pleistocene fossil record. The members of the two genera occupy distinct ecological niches and have different external appearances, but they are remarkably similar in their dental morphology, so that they were commonly thought of as undistinguishable in the fossil record. Thus, more or less all European Lemmini fossils have been assigned to the genus Lemmus. In the Early Pleistocene site of Schernfeld (Germany), the species Lemmus kowalskii had been described. It was thought by some authors that all Lemmini from Early to late Middle Pleistocene belong to this species.In the current study, we investigated Lemmini molar morphology from Western and Central European sites including Schernfeld (Early Pleistocene), Sackdillinger Höhle (Sackdilling Cave), and Koněprusy C718 (both early Middle Pleistocene), as well as other fossil localities with fewer specimens, formerly assigned to Lemmus kowalskii. Using an extensive modern referential material of Lemmus and Myopus, this study proposes to re-evaluate taxonomic status of the Middle and Early Pleistocene Lemmini. This modern referential also allows a better understanding of the morphology of Lemmus kowalskii specimens and its variability.Our results highlight the very high variation within fossil populations, as well as significant statistical differences between populations of the Early and Middle Pleistocene localities. A large part of these fossil specimens is firmly identified as Myopus sp., including the L. kowalskii holotype. Our identifications demonstrate that in most Early and Middle Pleistocene sites considered in this study, both genera (Lemmus and Myopus) are present. Possible interpretations and consequences for current view of lemming history are discussed, as well as some of the paleoecological and paleoenvironmental implications.

The Boiano Basin is one of the largest Quaternary intermontane basins of the central‐southern Apennines within one of the most tectonically active areas of the Mediterranean region. In order to reconstruct its entire Quaternary stratigraphic, tectonic, and palaeoenvironment evolution, lithofacies and palaeomagnetic analyses have been performed on a 900 m‐deep borehole (CP1) drilled in the southwestern sector of the basin. The Quaternary succession consists of an alternating of alluvial fan and fluvial–marshy deposits for a total thickness of 240 m, unconformably laying on Lower Miocene deposits of the Sannio Unit, thrusted on upper Miocene deposits of the Molise Flysch. In addition, the stratigraphic study and facies distribution of 29 intermediate and shallow wells drilled in the basin, allowing us to define the thickness and lithofacies variations of the Quaternary sedimentary units inside the entire Boiano Basin in the sector of Campochiaro alluvial fan. Our results demonstrate that the Boiano Basin infilling started during the late Early Pleistocene (c. 1.1 Ma) and developed with variation in lithofacies distribution and thickness. The first depositional unit (Early Pleistocene–early Middle Pleistocene in age) was palustrine and fluvial–marshy, the second (Middle Pleistocene in age) was characterized by the occurrence of the first cycle of alluvial fan deposition, the third (late Middle Pleistocene in age) was newly palustrine and fluvial marshy and, finally, the fourth recorded two cycles of alluvial fan deposition (late Middle Pleistocene and Late Pleistocene in age, respectively), interspersed by short periods of palustrinity, tephra layers deposition, and palaeosols development. The study allows the hypothesizing that the Quaternary infilling was accommodated within a graben (or semigraben) structure, affected mainly by extensional fault systems localized in the inner part of the basin and secondly by fault systems bounding the basin.

Ungulates from Atapuerca TD6

New Light on the Earliest Hominid Occupation in East Asia

From 1985 to 1987, four new localities with abundant fossil mammals were discovered by Cao, Tian and others in the Zhoukoudian (Choukoutien) area, Beijing. They are the East, West, Shangdian and Donglingzi caves. The East Cave fauna consists of 28 speices of mammals and its age is middle Early Pleistocene. The East Cave assemblage shows that a temperature–falling event took place at around 1.20 Ma B.P. at Zhoukoudian. Sixteen species of mammals were collected from the West Cave, which are mainly forms of late Early Pleistocene age. The West Cave fauna represents a transitional fauna from the East Cave fauna (dry–cold) to the fauna (warm) at locality 9. The Shangdian Cave fauna is composed of four forms, being Middle Pleistocene in age. The Donglingzi Cave fauna contains 21 Late Pleistocene forms. In the cave two fossil horizons may be distinguished. The age of the lower horizon is early Late Pleistocene, which is equivalent to that of the New Cave fauna; while the fauna of the upper horizon may be correlated with the Upper Cave fauna.

Taxonomical revision of fossil Canis in Middle Pleistocene sites of Zhoukoudian, Beijing, China and a review of fossil records of Canis mosbachensis variabilis in China

Overview of the geology and vertebrate biochronology of the Leisey Shell Pit Local Fauna, Hillsborough County, Florida

The Middle and Late Pleistocene mammalian faunas of Japan are described with new opinions on their succession and relation to the continental faunas. Although fossil materials assignable to early Middle Pleistocene are seemingly scarce in Japan, the fauna of that time is considered to have been transitional between the Early and Middle Pleistocene ones. On the other hand, fossil records which are younger than early Middle Pleistocene are abundant from the mainlands of Japan; viz. the Honshu-Shikoku-Kyushu area.In the middle Middle Pleistocene, the fauna of this area contained a considerable number of taxa which are extant today in the area (about 50%). It was also characterized by a high proportion of endemic species and the predominance of temperate forest elements. From this time to the late Middle Pleistocene, several species disappeared from the fauna; at the same time, immigrants from the continent were scarce. The faunal characters of the late Middle Pleistocene were basically identical with those of the preceding time.In the early Late Pleistocene, no mammal seems to have immigrated from the neighboring continent, and faunal composition was almost consistent with that of the late Middle Pleistocene. The elements of that fauna still persisted in the late Late Pleistocene, apart from the extinction of a few forms. In addition to the fact mentioned above, immigration from the northern part of the continent was recognized in the late Late Pleistocene, although it was restricted to a few large herbivore forms and to a short time duration.The introduction of the continental faunas to the mainlands of Japan during Middle and Late Pleistocene times was not so remarkable as previously inferred. Therefore it becomes doubtful that the faunas of the area were drastically replaced by the immigration of the Choukoutien, Wanhsien and Loess faunas of China during those times.

The occurrence of the genus Iberomys is testified in Italy and the Iberian Peninsula from the Early Pleistocene on. The genus comprises two extinct voles: I. huescarensis from the Early Pleistocene to the early Middle Pleistocene and I. brecciensis (=mediterraneus) from the Middle to the early Late Pleistocene. I. cabrerae, has been present in Spain from the early Late Pleistocene, enduring right through to today. The fossil record of Iberomys in Italy is poor in comparison with those in the Iberian Peninsula and southern France. I. huescarensis has been identified in Italy at the Rifreddo and Spessa sites, while I. brecciensis has been recognized at Zoppega 2, Montagnola Senese II, Isernia, Valdemino, Polledrara di Cecanibbio and Paglicci. A revision of the specimens of the genus Iberomys in Italy and a comparison with the fossil records of southern France and the Iberian Peninsula show that the origin of the Early Pleistocene species (I. huescarensis) is clearly in the Iberian Peninsula, where the species having evolved from ancient populations of Allophaiomys nutiensis. The origin of the species I. brecciensis is still unknown. It seems to appear at the same time in Italy and in the Iberian Peninsula, and its extinction occurred during the late Middle Pleistocene-early Late Pleistocene in Italy, France and Iberia simultaneously.

Since the oldest known Acheulean lithic techno-typological features in Europe were reported at the site of Barranc de la Boella (Tarragona, Spain), continuous fieldwork has been conducted there in archeological deposits of the late Early Pleistocene age (0.99–0.78 Ma). As a result, excavations in two of the three open-air localities have significantly expanded the collection of lithic and faunal remains, allowing us to make progress in the interpretation of the hominin behaviors in an open-air fluvial-deltaic sedimentary environment. This includes examples of cumulative palimpsests, such as those found at the locality of La Mina, in which hominins only had a minimal role as modifying agents, as well as the extraordinary mammoth butchery site recorded at the Pit 1 locality. The aim of this paper is to present a comprehensive update of the collection of large shaped tools and to assess its significance in the framework of the earliest occurrence of the Acheulean in Europe. This cultural entity is increasingly well-documented for the early Middle Pleistocene, but very little is known about its presence in Europe before the Brunhes–Matuyama boundary. Large shaped tools appear in the three localities explored in the Unit II of Barranc de la Boella, including choppers (unifacial and bifacial) and standard Acheulean forms, such as picks, knives, and cleaver-like forms. Techno-typological and morphometrical analyses revealed a basic heavy-duty component obtained through simple shaping sequences coupled with significantly more elaborate tools produced on various large blanks (cobbles, slabs, or flakes). The complete bifacial and bilateral shapings have yet to be documented, but the present specific tool assemblage attests to the Early Acheulean technological threshold. Hence, the archaeological data from Barranc de la Boella provide insights into the first appearance of the Acheulean technology in Europe and add critical information to the debate on the technological variability of the Early Pleistocene hominin occupation of the continent. The results of this study revealed a technological assemblage unique in the known late Early Pleistocene archeological record from Europe, different from the rest of ancient Acheulean sites in this continent, which are dated at the Middle Pleistocene. This lends support to the hypothesis that Barranc de la Boella may represent a previously unrecognized Early Acheulean dispersion out of Africa connected to its first evidence at the gates of Eurasia, potentially moving over the northern Mediterranean coastal road to reach Western Europe.

Xenocyon lycaonoides is a well-represented large canid known from the middle Early Pleistocene to Middle Pleistocene in Europe, central Asia, and Alaska, yet its fossil record in eastern Asia is extremely poor. Here we report a well-preserved palatal part of the skull of this species from Jinyuan Cave of Luotuo Hill, Puwan, Dalian of Liaoning Province, northeastern China. The new material confirms the presence of this species in eastern Asia during the early Middle Pleistocene, supporting a Holarctic distribution of this lineage during the Mid-Pleistocene climate change. The morphology of the new material suggests that the Middle Pleistocene X. lycaonoides is more derived than the late Early Pleistocene population, and is distinct from the living Lycaon pictus, and imply the different evolutionary direction from Lycaon. Our analyses support a generic distinction of the Xenocyon from Lycaon. X. lycaonoides can not be the direct ancestor of Lycaon, but is a related taxon that lived in Eurasia and North America. The lineage includes Xenocyon, and Lycaon Brookes, 1827, and partially contributes to Cynotherium Studiati, 1857, showing two independent Island specialisation events, making it one of the most successful lineages of canids ever known.

The lithic industry of Sima del Elefante (Atapuerca, Burgos, Spain) in the context of Early and Middle Pleistocene technology in Europe

Discovery of Enhydrictis (Mustelidae, Carnivora, Mammalia) cranium in Puwan, Dalian, Northeast China demonstrates repeated intracontinental migration during the Pleistocene

Fossil remains and the technological complexes recorded in archaeological sites suggest that the human presence in Europe late in the early and middle Pleistocene was discontinuous. Moreover, competition for meat with other secondary consumers could have delayed the human dispersal through Europe. However, evaluation of the extent competition intensity among secondary consumers suggests this influenced the discontinuity of the human settlement of Europe between 1.1 and 0.2 Ma. Using a mathematical model, we estimate the amount of biomass available in a community for secondary consumers. The amount of available biomass is subsequently distributed among the guild of secondary consumers according to their requirements and prey preferences. Indexes that quantify the competition intensity among secondary consumers to compare the conditions in different paleoecosystems show that the competition intensity late in the early Pleistocene, early in the middle Pleistocene, and late in the middle Pleistocene does not support the view that an increase in competition intensity constrained the expansion of human populations early in the middle Pleistocene. Somewhat paradoxically, the lowest competition intensity is estimated to have occurred early in the middle Pleistocene, most likely because of an increase in the number of large herbivore species and a decrease in the number of secondary consumers. The early Pleistocene paleoecosystems supported higher competition intensity than the middle Pleistocene ecosystems, likely because of the different configuration in the food webs of these two periods (the early and middle Pleistocene).