Early Miocene Fossil Research Articles

A New Late Early to Early Middle Miocene Fossil Baleen Whale Aff. Isanacetus laticephalus Specimen from Hokkaido, Japan

A New Late Early to Early Middle Miocene Fossil Baleen Whale Aff. Isanacetus laticephalus Specimen from Hokkaido, Japan

Large-sized pentadactyl carnivore footprints from the early Miocene fossil track site at Ipolytarnóc (Hungary): 3D data presentation and ichnotaxonomical revision

ABSTRACT Ipolytarnóc is one of the most important Cenozoic fossil trackway sites in Europe. Most of the discovered footprints were investigated in 1985; however, a considerable period has elapsed since those investigations, and during that time significant advances have been made in the field of 3D imaging. Given this fact, the present study was undertaken to carry out a new analysis of the Ipolytarnóc fossil tracks, with a view to present possible revisions of current knowledge. In line with this, detailed ichnotaxonomical analyses were conducted on two large-sized pentadactyl footprint types using high-quality 3D models. As a result of the investigations presented in this paper, the largest pentadactyl footprint-type (previously defined as Bestiopeda maxima) was reclassified under the Platykopus ichnogenus based on new materials and their 3D models. The P. maxima footprints are believed to represent those of large-sized Amphicyonidae. Thorough ichnotaxonomical analyses were performed on other pentadactyl fossil tracks which had been attributed to Carnivoripeda nogradensis. The aim of the analyses was to suggest an extension of the morphological characters of these ichnospecies. In contrast to the previously suggested Nimravidae origin, we rather suggest that the C. nogradensis footprints belong to a mustelid-like carnivore based on its footprint morphology.

Additional hominoid fossils from the early Miocene of the Lothidok Formation, Kenya.

Hominoid fossils are abundant at early Miocene fossil sites in the Lothidok Range, located directly west of Lake Turkana in northern Kenya. The West Turkana Miocene Project (WTMP) has worked in the Lothidok Range since 2008 with the goal of further elucidating the paleobiology of the hominoids through the recovery of new specimens and detailed documentation of their paleoecological context. To date our research has focused largely on the Kalodirr and Moruorot Site Complexes, both radiometrically dated to ~17.5-16.8Ma. Our ongoing fieldwork at the Kalodirr Site Complex resulted in the discovery of new dentognathic specimens of the three previously identified species of fossil hominoids-Turkanapithecus kalakolensis, Simiolus enjiessi, and Afropithecus turkanensis. A new mandible and an isolated M3 of T. kalakolensis from Kalodirr further clarify the lower molar morphology of the species and permit identification of KNM-MO 1 as a mandible of T. kalakolensis. A new mandible of S. enjiessi provides evidence of the relative proportions of the first and second lower molars. A new male specimen of A. turkanensis shows unusual P4 morphology that may be a developmental anomaly or a previously unknown morphological variant. An improved understanding of the lower molar morphology of T. kalakolensis further strengthens its identification as a nyanzapithecine. Our new specimens and subsequent re-identification of existing collections makes it clear that all three Lothidok hominoids are known from both the Moruorot and Kalodirr Site Complexes. The Lothidok Range holds great promise for further documenting hominoid evolution.

Elevated CO<sub>2</sub>, increased leaf-level productivity, and water-use efficiency during the early Miocene

Abstract. Rising atmospheric CO2 is expected to increase global temperatures, plant water-use efficiency, and carbon storage in the terrestrial biosphere. A CO2 fertilization effect on terrestrial vegetation is predicted to cause global greening as the potential ecospace for forests expands. However, leaf-level fertilization effects, such as increased productivity and water-use efficiency, have not been documented from fossil leaves in periods of heightened atmospheric CO2. Here, we use leaf gas-exchange modeling on a well-preserved fossil flora from early Miocene New Zealand, as well as two previously published tropical floras from the same time period, to reconstruct atmospheric CO2, leaf-level productivity, and intrinsic water-use efficiency. Leaf gas-exchange rates reconstructed from early Miocene fossils, which grew at southern temperate and tropical latitudes when global average temperatures were 5–6 ∘C higher than today, reveal that atmospheric CO2 was ∼450–550 ppm. Early Miocene CO2 was similar to projected values for 2040 CE and is consistent with an Earth system sensitivity of 3–7 ∘C to a doubling of CO2. The Southern Hemisphere temperate leaves had higher reconstructed productivity than modern analogs, likely due to a longer growing season. This higher productivity was presumably mirrored at northern temperate latitudes as well, where a greater availability of landmass would have led to increased carbon storage in forest biomass relative to today. Intrinsic water-use efficiency of both temperate and tropical forest trees was high, toward the upper limit of the range for modern trees, which likely expanded the habitable range in regions that could not support forests with high moisture demands under lower atmospheric CO2. Overall, early Miocene elevated atmospheric CO2 sustained globally higher temperatures, and our results provide the first empirical evidence of concomitant enhanced intrinsic water-use efficiency, indicating a forest fertilization effect.

The large-sized darter Anhinga pannonica (Aves, Anhingidae) from the late Miocene hominid Hammerschmiede locality in Southern Germany.

We report fossils of the darter Anhinga pannonica Lambrecht, 1916 from two late Miocene (Tortonian, 11.62 and 11.44 Ma) avifaunas in Southern Germany. The material from the hominid locality Hammerschmiede near Pforzen represents the most comprehensive record of this species and includes most major postcranial elements except for the tarsometatarsus. We furthermore show that the putative cormorant Phalacrocorax brunhuberi (von Ammon, 1918) from the middle Miocene of Regensburg-Dechbetten is another, previously misclassified, record of A. pannonica, and this may also be true for early Miocene fossils described as P. intermedius Milne-Edwards, 1867. A. pannonica was distinctly larger than extant darters and reached the size of A. grandis from the late Miocene of North America. We detail that only fossils from the Miocene of Europe and Africa can be referred to A. pannonica, whereas putative records from Asia fall within the size range of extant darters. A. pannonica appears to have been a long-living species (16 to 6 Ma) with an extensive distribution from the equator to the northern mid-latitudes. The extinction of large-sized darters in Europe is likely to have been due to climatic cooling in the late Neogene, but the reasons for their disappearance in Africa and South America remain elusive.

Paleosol-based inference of niches for Oligocene and early miocene fossils from the John Day Formation of Oregon

ABSTRACT Over the past decade, we recorded exact locations of in situ fossils and measured calcareous nodules in paleosols of the Oligocene and lower Miocene (Whitneyan–Arikareean) John Day Formation of Oregon. These data enable precise biostratigraphy within an astronomical time scale of Milankovitch obliquity cycles and also provide mean annual precipitation and vegetation for each species. Fossils in paleosols of the John Day Formation alternated between semiarid shrubland and subhumid woodland communities every 41 ka. Land snails ‘Polygyra’ expansa and Monadenia dubiosa were found in semiarid paleosols, but Vespericola dalli and Monadenia marginicola were found in subhumid paleosols. Cicada burrows (Naktodemasis bowni) were found in semiarid paleosols, whereas dung beetle balls (Pallichnus dakotensis) and earthworm castings (Edaphichnium lumbricatum) were found in subhumid paleosols. Among hypertragulids, Hypertragulus hesperius was found in semiarid paleosols and Nanotragulus planiceps in subhumid paleosols. Among glires, the aplodontiid Haplomys liolophus, geomyids Pleurolicus sulcifrons and several species of Entoptychus, castorid Palaeocastor peninsulatus, and leporid Archaeolagus ennisianus were found in semiarid paleosols. Large ungulates were found primarily in subhumid paleosols, including the agriochoere Agriochoerus antiquus, oreodonts Eporeodon occidentalis and Promerycochoerus superbus, equid Miohippus annectens, and rhinos Diceratherium annectens and Diceratherium armatum. The inferred niches of fossil mammals are consistent with interpretations based on their morphology; taxa with adaptations for life in open, arid habitats, such as high-crowned teeth and semifossorial or cursorial limb structure, were mainly in semiarid paleosols, but taxa with arboreal adaptations were only found in subhumid paleosols.

A new early Miocene fossil genus from Dominican amber extends the Eastern Asia distribution of Paricanini (Hemiptera: Fulgoromorpha: Tropiduchidae) to the Neotropics

A new early Miocene fossil genus from Dominican amber extends the Eastern Asia distribution of Paricanini (Hemiptera: Fulgoromorpha: Tropiduchidae) to the Neotropics

Biostratigraphy, magnetostratigraphy, and geochronology of lower Miocene Aoerban strata in Central Inner Mongolia

The Aoerban region of central Inner Mongolia, China is an important early Miocene fossil site that contains a diverse mammalian record unrivaled by other Asian sites of similar age. In this paper, we present lithostratigraphic, biostratigraphic, and magnetostratigraphic data from Aoerban Formation to better understand faunal changes between the Xiejian and Shanwangian Chinese Land Mammal ages. With new biochronological constraints, magnetochrons in the Aoerban Formation can be correlated to C6An.2n to C5Cr with an age range of 20.71–16.72 Ma of the Astronomically Tuned Neogene Timescale (ATNTS2012). The strata of the Aoerban region contain a number of important mammalian First Appearance Data, including several morphotypes of deer (Cervidae), horses (Anchitherium), pika (Alloptox), cricetid rodents (Megacricetodon), and possibly the local earliest record of gomphotheres (i.e., the Proboscidea event). Although the ranges for most of these taxa are still poorly known, some of them, alone or in combination, are useful in defining the base the Shanwangian Land Mammal Age. Within this finely calibrated chronologic framework, the faunas of the Aoerban region are important for better understanding mammalian evolution, biogeography, and paleoenvironment.

Late Cretaceous–Palaeogene topography of the Chinese Tian Shan: New insights from geomorphology and sedimentology

The Cenozoic growth of the intra-continental Tian Shan Range initiated during the late Eocene–Oligocene, and led to a tectonic reactivation of the complex Palaeozoic and Mesozoic lithospheric structure. Due to the very low erosion rates linked to the semi-arid climate that characterised the Tian Shan region during most of the Cenozoic, the topography of the range is not at equilibrium with deformation. Fragments of pre-orogenic low relief surfaces are preserved among the Late Cenozoic Alpine-type topography. Using field observations and satellite image mapping of those fragments, as well as sedimentology and biostratigraphic analysis, we show that the pre-Oligocene topography of the Tian Shan region was indeed complex, combining hundreds of metres to one-and-a-half kilometre-high reliefs with a multi-phased Mesozoic planation surface incised by Late Mesozoic paleo-valleys. The occurrence of several metres-thick Late Cretaceous–Palaeogene calcareous paleosols, in the basins surrounding the range further implies a semi-arid climate, very low subsidence rates and no uplift at that time. Late Cretaceous and early Miocene fossil records in the northern Tian Shan suggest a possible connection, even if episodic, between the drainage system of the south Junggar foreland basin and the proto-Paratethys Sea to the west. A renewed late Eocene–early Oligocene sedimentation probably marks the onset of the Tian Shan uplift. We argue that in addition to the growth of the Pamir and Western Kunlun ranges, this incipient uplift was one of the driving mechanisms for the final retreat of the proto-Paratethys Sea from the Tarim Basin. This regression apparently did not change the climate in the studied area because semi-arid conditions seem to prevail at least since the Late Cretaceous. Finally, the Tian Shan uplift remained very limited up to the Miocene as revealed by the occurrence of Burdigalian lake deposits preserved in the paleo-valleys inside the present day range. In contrast, post-early Miocene deformation of the northern Tian Shan has produced 4000 to 5000 m of differential vertical movement between the uplifted range and the subsiding proximal foreland basin.

Lower Miocene alligatoroids (Crocodylia) from the Castillo Formation, northwest of Venezuela

Crocodyliform diversity was particularly high during the middle and late Miocene of South America, with up to 12 species recovered from a single geological unit. Nonetheless, the early Miocene fossil record of low-latitude vertebrates is scarce; hence, crocodylians remain poorly known in the region. The Castillo Formation, located in the northwest of Venezuela, preserves an interesting vertebrate fauna with a well-constrained late early Miocene age. Previous work dealing with crocodylians of this formation only recorded three taxa: the gavialoid Siquisiquesuchus venezuelensis and Gryposuchus sp. and indeterminate alligatoroid remains. New cranial and mandibular material recently recovered from the Castillo Formation allows us to document four previously unrecognised alligatoroid forms: Purussaurus sp., Caiman sp., an indeterminate caimanine and an indeterminate alligatoroid. With six taxa, the crocodylian assemblage reveals a previously undocumented relatively high taxonomic diversity in the early Miocene. The Castillo crocodylians show a broad range of morphological disparity and body sizes ranging from small (2.5 m–62 kg) to large (7.5 m–1600 kg) taxa. Thus, crocodylian niche partition, as well as the abundance and variety of resources and environmental heterogeneity of aquatic ecosystems in South America, were already established by at least the early Miocene. The presence of Caiman in ~ 18 Ma strata represents the unequivocally earliest record of the taxon in South America and allows us to propose that the origin of the jacareans is more likely to have occurred during or before the early Miocene, challenging previous molecular hypotheses.

Systematic revision of the early Miocene fossil Pseudoepicrates (Serpentes: Boidae): implications for the evolution and historical biogeography of the West Indian boid snakes (Chilabothrus)

Systematic revision of the early Miocene fossil Pseudoepicrates (Serpentes: Boidae): implications for the evolution and historical biogeography of the West Indian boid snakes (Chilabothrus)

Evidence for rapid faunal change in the early Miocene of East Africa based on revised biostratigraphic and radiometric dating of Bukwa, Uganda

Field expeditions to Bukwa in the late 1960s and early 1970s established that the site had a small but diverse early Miocene fauna, including the catarrhine primate Limnopithecus legetet. Initial potassium-argon radiometric dating indicated that Bukwa was 22 Ma, making it the oldest of the East African early Miocene fossil localities known at the time. In contrast, the fauna collected from Bukwa was similar to other fossil localities in the region that were several million years younger. This discrepancy was never resolved, and due to the paucity of primate remains at the site, little subsequent research took place.We have collected new fossils at Bukwa, reanalyzed the existing fossil collections, and provided new radiometric dating. 40Ar/39Ar incremental heating ages on lavas bracketing the site indicate that the Bukwa fossils were deposited ∼19 Ma, roughly 3 Ma younger than the original radiometric age. Our radiometric dating results are corroborated by a thorough reanalysis of the faunal assemblage. Bukwa shares taxa with both stratigraphically older localities (Tinderet, Napak) and with stratigraphically younger localities (Kisingiri, Turkana Basin) perfectly corresponding to our revised radiometric age.This revised age for Bukwa is important because it indicates that significant faunal turnover may have occurred in East Africa between 20 and 19 Ma. Bukwa samples immigrant taxa such as large suids, large ruminants, and ochotonids that are absent from stratigraphically older but well-sampled localities in the region, such as Tinderet (∼20 Ma) and Napak (20 Ma). Further age refinements for Bukwa and the entire East African early Miocene sequence will help to constrain the timing of this faunal turnover event, of particular importance in paleoanthropology since this temporal sequence also provides us with what is currently our best window into the early evolution of cercopithecoid and hominoid primates.

Catarrhine hallucal metatarsals from the early Miocene site of Songhor, Kenya

Songhor is an early Miocene fossil locality in Kenya known for its diverse primate assemblage that includes catarrhine species belonging to the genera Kalepithecus, Limnopithecus, Dendropithecus, Rangwapithecus, and Proconsul. Expeditions to Songhor since the 1930s have recovered unassociated catarrhine postcranial remains from both the fore- and hindlimbs, including multiple elements from the feet. In this study, we describe KNM-SO 31233, a complete left hallucal metatarsal (Mt1), along with several other fragmentary Mt1 specimens (KNM-SO 1080, 5129, 5141, 22235). These fossils were compared to extant catarrhines and platyrrhines, as well as available fossil Miocene catarrhine Mt1s. Morphometric data were obtained from 3D surface renderings and subjected to a number of analyses to assess their phenetic affinity with the comparative sample, make predictions of body mass, and to infer their functional morphology. The size and shape of the Songhor Mt1s are diverse, exhibiting a large robust morph (KNM-SO 5141) similar in size but not in shape to extant African apes, medium-sized morphs (KNM-SO 1080, 5129 and 22235), and a smaller, slender one (KNM-SO 31233) that has a shape resembling arboreal quadrupedal leaping monkeys and suspensory atelines and hylobatids. KNM-SO 31233 is unlike other known fossil Mt1s, and in general, none of the Songhor Mt1s resembled any single extant anthropoid clade or species. The morpho-functional diversity of Songhor Mt1s is consistent with an extensive morphological and phylogenetic catarrhine diversity in the early part of the Miocene epoch.

The fishes of Bukwa, Uganda, a lower Miocene (Burdigalian) locality of East Africa

ABSTRACTRenewed research at the early Miocene fossil site of Bukwa in northeastern Uganda has resulted in new fossil finds, including fish, with representatives of two families, Cichlidae and Alestidae. Although the two families were previously briefly reported from Bukwa, we here give a more detailed account of the fishes based on newly collected material. The cichlid material, mainly composed of vertebrae, can be tentatively assigned to one or more species of Pseudocrenilabrinae. The alestid material, comprising a diversity of teeth, likely represents several different species of Alestes, Brycinus, and/or Bryconaethiops. Although the ichthyofaunal diversity of Bukwa is low, the fishes are important for indicating the paleoenvironment and hydrographic connections of Bukwa. The early Miocene was a critical time for African faunas, because it was during this time that the Afro-Arabian and Eurasian plates came into contact with one another, ending the long isolation of Africa, which, along with rifting in East Africa, created new terrestrial and hydrological connections allowing faunal interchanges. Bukwa is one of only a few African early Miocene localities known that sample fish and, based on these fish, the site probably represents an area of interconnected lakes and large rivers, including floodplains.SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVPCitation for this article: Murray, A. M., T. Argyriou, S. Cote, and L. MacLatchy. 2017. The fishes of Bukwa, Uganda, a lower Miocene (Burdigalian) locality of East Africa. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1324460.

First African record of the Miocene Asian mouse-deer Siamotragulus (Mammalia, Ruminantia, Tragulidae): implications for the phylogeny and evolutionary history of the advanced selenodont tragulids

New remains of the small tragulid Dorcatherium songhorensis Whitworth, 1958 from the Early Miocene fossil site of Napak XXI (Uganda) include the first significant sample of postcranial bones from this species ever described. The limb bones of this tragulid are very similar to that described in the Miocene Asian long-legged tragulids of the genus Siamotragulus Thomas et al., 1990, a type previously unknown in the African Miocene. A cladistic analysis links D. songhorensis to a Siamotragulus clade as its basal offshoot, so we propose the name Siamotragulus songhorensis (Whitworth, 1958) for this species. Also, the Siamotragulus clade belongs to a monophyletic group that includes Afrotragulus Sánchez et al., 2010 and the extant Asian genera Moschiola and Tragulus. This inclusive clade is characterized by both a derived selenodont dentition and an advanced postcranial skeleton. Additionally Siamotragulus shows some cursorial refinements reflected in its postcranial skeleton including the pecoran-like metatarsals III–IV. Siamotragulus songhorensis shows that the genus Siamotragulus was not endemic to Asia as previously thought, and that a highly diverse guild of tragulids, including different members of the advanced selenodont clade, inhabited Africa as early as the Early Miocene (19–20 Ma).

Remnants of an ancient forest provide ecological context for Early Miocene fossil apes

The lineage of apes and humans (Hominoidea) evolved and radiated across Afro-Arabia in the early Neogene during a time of global climatic changes and ongoing tectonic processes that formed the East African Rift. These changes probably created highly variable environments and introduced selective pressures influencing the diversification of early apes. However, interpreting the connection between environmental dynamics and adaptive evolution is hampered by difficulties in locating taxa within specific ecological contexts: time-averaged or reworked deposits may not faithfully represent individual palaeohabitats. Here we present multiproxy evidence from Early Miocene deposits on Rusinga Island, Kenya, which directly ties the early ape Proconsul to a widespread, dense, multistoried, closed-canopy tropical seasonal forest set in a warm and relatively wet, local climate. These results underscore the importance of forested environments in the evolution of early apes.

Early Miocene fossil frogs (Anura: Leiopelmatidae) from New Zealand

The first pre-Quaternary anurans from New Zealand are reported from the Early Miocene (19–16 Ma) St Bathans Fauna based on 10 fossil bones. Four bones representing two new species differing in size are described in Leiopelma: Leiopelmatidae, and are the first Tertiary records for the family. Six indeterminate frog fossils are morphologically similar to leiopelmatids and represent two species consistent in size with those known from diagnostic material. These records are highly significant, as minimally, they reduce the duration of the leiopelmatid ‘ghost lineage’ by c.20 million years and demonstrate that a diversity of leiopelmatids has long been present on New Zealand, supporting the ancient dichotomy of the extant species based on molecular data.Leiopelma miocaenale Worthy, Tennyson, Scofield & Hand in pressurn:lsid:zoobank.org:act:83F24868-A212-435B-B892-AD510796B5BBLeiopelma acricarina Worthy, Tennyson, Scofield & Hand in pressurn:lsid:zoobank.org:act:D3955F53-37C2-4EAD-B0BC-CE8D23FCD51B

Divergence Times and the Evolutionary Radiation of New World Monkeys (Platyrrhini, Primates): An Analysis of Fossil and Molecular Data.

The estimation of phylogenetic relationships and divergence times among a group of organisms is a fundamental first step toward understanding its biological diversification. The time of the most recent or last common ancestor (LCA) of extant platyrrhines is one of the most controversial among scholars of primate evolution. Here we use two molecular based approaches to date the initial divergence of the platyrrhine clade, Bayesian estimations under a relaxed-clock model and substitution rate plus generation time and body size, employing the fossil record and genome datasets. We also explore the robustness of our estimations with respect to changes in topology, fossil constraints and substitution rate, and discuss the implications of our findings for understanding the platyrrhine radiation. Our results suggest that fossil constraints, topology and substitution rate have an important influence on our divergence time estimates. Bayesian estimates using conservative but realistic fossil constraints suggest that the LCA of extant platyrrhines existed at ca. 29 Ma, with the 95% confidence limit for the node ranging from 27–31 Ma. The LCA of extant platyrrhine monkeys based on substitution rate corrected by generation time and body size was established between 21–29 Ma. The estimates based on the two approaches used in this study recalibrate the ages of the major platyrrhine clades and corroborate the hypothesis that they constitute very old lineages. These results can help reconcile several controversial points concerning the affinities of key early Miocene fossils that have arisen among paleontologists and molecular systematists. However, they cannot resolve the controversy of whether these fossil species truly belong to the extant lineages or to a stem platyrrhine clade. That question can only be resolved by morphology. Finally, we show that the use of different approaches and well supported fossil information gives a more robust divergence time estimate of a clade.

A morphotype catalog and paleoenvironmental interpretations of early Miocene fossil leaves from the Hiwegi Formation, Rusinga Island, Lake Victoria, Kenya

Early Miocene deposits on Rusinga Island (Lake Victoria, Kenya) contain an abundance of faunal and floral remains. Despite the attention that has historically been given to the early Miocene fauna from Rusinga Island, little attention has been given to the early Miocene fossil floras and to date no studies have described fossil leaf morphotypes from Rusinga Island. Here, we present a morphotype catalog of fossil leaves collected from the Grit Member of the Hiwegi Formation on Rusinga Island. We describe 14 morphotypes, comprised of 12 dicotyledonous angiosperms and two monocotyledonous angiosperms, as well as two distinct dicotyledonous angiosperm leaf fragments. Characteristics of the flora and sedimentological evidence, coupled with previous research, suggest that the local paleoenvironment was a riparian habitat within a patchwork of woodland and forested biomes in what was likely a warm climate. This work represents an important first step in understanding the early Miocene vegetation of Rusinga Island, and highlights both the need and potential for future research on these early Miocene floras.

Lorisine Primate from the Late Miocene of Kenya

The origin of African Lorisidae has been the subject of debate for the past half century, so far without resolution. The matter is complecated by the fact that strepsirrhines (Lorisiformes = Lorisidae + Galagidae) are rare in the African fossil record, with large gaps between occurrences in the Early Oligocene Fayum (Egypy) deposit, the Early Miocene strata of East Africa and the Plio-Pleistocene of the same region. Likewise, the Asian fossil record of this group is spotty, with only a few specimens described from the Late Miocene of Pakistan. In the search for evidence concerning the dichotomy between Lorisidae and Galagidae, authors have tended to focus on the Early Miocene fossils from Kenya and Uganda which is the only region to have yielded a reasonable diversity of forms. Unfortunately, the history of study has been marred by the description and interpretation of non-primate material as strepsirrhines (Lorisiformes spurii). This contrasts with the genuine strepsirrhine (Lorisiformes veri) fossil from the same region which have thrown much light on the group, but which have not yet resolved the issue of the timing or the modality of the dichotomy between the two families. At present, among the described African fossil lorisiformes only the genus Mioeuoticus is accepted by some, but not all, authors (Harrison, 2010) as a Lorisidae (or Lorisinae, all the others generally being classed as Galagidae (or Galginae) Walker (1987). It is thus of interest to put on record the discovery of a lorisid anout from the Late Miocene deposits of the Tugen Hills, Kenya, which is close in dimensions and some aspects of the Far East (Nycticebus, Nycticeboides) and West Africa (Arctocebus). The fossil does not particularly resemble any of the Early Miocene forms described from East Africa, and it is suggested that the lineage entered Africa during the Late Miocene at the same time that several other vertebrate groups spread into the continent from South-East Asia.