The Rubiaceae of Cabinda (Angola)

A treatment of the Rubiaceae of Cabinda (Angola) is presented based on various herbarium collections. There are 67 genera and 169 species of Rubiaceae represented in the flora of Cabinda. Eight entities are unnamed and could represent new taxa. Identification keys are provided for species and infraspecific taxa. A new combination is made in Rothmannia and two are made in Psychotria. A new name is provided in Psychotria . Eighteen taxa are endemic to Cabinda, two of which are also endemic to Angola. The conservation status of the endemic taxa is unknown due to the lack of collections over the last 40 years. © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 154 , 455–495.     

First record of a parapithecid primate from the Oligocene of Kenya

Recent excavations in northwestern Kenya have recovered a vertebrate fauna of late early or early late Oligocene age. Among the mammal remains, a fragmentary lower jaw and an isolated upper molar have been attributed to a small primate, Lokonepithecus manai gen. et sp. nov. Lokonepithecus is a primitive member of the Parapithecidae and possibly most closely related to Apidium from the Fayum. The new primate from Kenya is the youngest parapithecid known and its occurrence in the Oligocene of Kenya suggests that sub-Saharan Africa probably played a major role in the evolutionary history of several groups of mammals.     

Presence of the large aquatic snake Palaeophis africanus in the middle Eocene marine margin of the Congo Basin,Cabinda, Angola

Ten isolated snake vertebrae from Landana and Sassa-Zao, Cabinda Exclave, Angola, present a “primitive” grade morphology with a weak lateral compression and do not belong to Palaeophis aff. typhaeus as originally referred to. They well belong to a single taxon and are here attributed to Palaeophis africanus for which the intracolumnar variation is described and illustrated. This species is Lutetian (middle Eocene) in age and originates from a marine coastal environment confirming again the aquatic capabilities of palaeophiid snakes. It represents the third largest species of Palaeophis with P. colossaeus and P. maghrebianus to which it is closely related in our tentative phylogenetic analysis, indicating that these three taxa could belong to an African clade. This study also contributes to the debate on the existence of primitive and advanced grades among palaeophiid snakes. Palaeophis presents laterally compressed anterior trunk vertebrae that could have been often erroneously considered as representing advanced grade species and potential parataxonomy.     

Dioscoreaceae fossils from the late Oligocene and early Miocene of Ethiopia

Dioscorea section Lasiophyton leaflets from the late Oligocene (27.23 Ma) and Tacca leaves from the early Miocene (21.73 Ma) of north‐western Ethiopia greatly expand the known fossil record of Dioscoreaceae and represent the earliest and only known records of the Afro‐Asian trifoliate, palmately veined yams (Dioscorea) and bat flowers (Tacca). Both fossils occur in volcaniclastic and clastic sediments associated with a high water table, and the palaeofloral assemblages are indicative of tropical moist forest formations. These fossils provide insight into the evolutionary history of the family in Africa during the mid‐Cenozoic and provide well‐dated taxa that can assist in phylogenetic analyses and evolutionary divergence studies for Dioscoreales and Dioscoreaceae. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175 , 17–28.     

New remains of Chambius kasserinensis from the Eocene of Tunisia and evaluation of proposed affinities for Macroscelidea (Mammalia,Afrotheria)

Abstract

Chambius kasserinensis from the late Early or early Middle Eocene Chambi locality, central Tunisia, is undoubtedly the oldest known macroscelidid and possibly the basalmost representative of the order Macroscelidea. Hence, since its discovery in 1986, Chambius has played a key role in analyses focusing on afrotherian and eutherian phylogeny; for instance, as early as 1995, Butler’s review of fossil macroscelideans highlighted the central position of Chambius in the origin of the order. Despite this, Chambius remained poorly known until recently. Here based on new mandibular fragments, well-preserved upper molars and CT scan analysis of the holotype maxilla, Chambius is revised. Its dentition is first described in detail, providing a precise characterization of the genus. Chambius is notably defined by a submolariform P₄ with a three-cusped talonid, a reduced talonid on M₂, and a prominent metaconule on M^1?2. Interestingly, the two transverse lophs of the upper molars are basically formed by preconulecristae, evoking the recently defined peculiar bilophodonty of paenungulates. Comparisons with other Paleogene and modern macroscelidids, European Louisinidae, and North American Apheliscidae are also made, allowing the various hypotheses about the origin and early evolution of macroscelidids to be reviewed.     

Brief communication: Plio‐Pleistocene eagle predation on fossil cercopithecids from the Humpata Plateau,southern Angola

Recent studies suggest a large raptor such as the crowned eagle (Stephanaoetus coronatus) was responsible for collecting at least a portion of the primate fauna from the South African fossil site of Taung, including its lone hominin specimen. This taphonomic signature at Taung is currently regarded as a unique and, most likely, isolated case in primate and human evolution. However, the activities of large, carnivorous birds should also be detectable at other primate fossil localities in Africa if raptors have been a strong selective force throughout primate evolution. Over the last 60 years, a collection of extinct cercopithecids has been assembled from several cave breccias on the Humpata Plateau in southern Angola. The material, dated near the Plio‐Pleistocene boundary, includes an assortment of craniodental and postcranial remains variably assigned to Papio (Dinopithecus) cf. quadratirostris, Parapapio, Cercopithecoides, and Theropithecus. We compare the Angolan and Taung material to remains of extant primates killed by crowned eagles in the Ivory Coast's Tai National Park. Our analysis indicates that the size distribution and composition of fauna from the localities is quite similar and that there are striking consistencies in damage to the crania from each site. The absence of large bodied (>20 kg) primates and other mammalian taxa at the Taung hominin locality and Tai, and their rarity in Angola, combined with the strong likelihood that raptor nests were positioned near fissure openings at both fossil localities, provides additional support for eagle involvement. On the basis of this evidence, we conclude that at least some of the Angolan cercopithecids were most likely raptor prey and hypothesize that raptor predation has been a strong and perhaps underappreciated selective force during the course of primate evolution. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc.     

The Rubiaceae of Angola

A treatment of the Rubiaceae of Angola is presented based on herbarium collections kept at BM, BR, COI, K, LISC, LISU, LUA, LUAI, P, and PRE. The basionyms, relevant synonyms, and types from Angola are cited. For each taxon, one collection is cited for each province. An exsiccata list with over 3300 collections examined and identified during this work is provided. There are 108 genera, 422 species, and 40 infraspecific taxa of Rubiaceae in Angola. Fourteen genera and 126 species and infraspecific taxa are restricted to Cabinda. The rate of endemism of the family is c. 19%, with 86 taxa endemic to Angola (16 of which are restricted to Cabinda). Two genera are endemic. A new subspecies and a new variety are described. There are 21 unnamed entities requiring further research. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 537–638.     

A review of cetacean occurrence in West African waters from the Gulf of Guinea to Angola

• 1 The cetacean fauna of the west coast of Africa is poorly described. Therefore, literature on the occurrence of cetacean species in the waters of 13 potential West African range states from the Gulf of Guinea to Angola was reviewed, including sighting, stranding, capture, bycatch and whaling records.
• 2 At least 28 species of cetacean were documented in the study region, comprising seven baleen whale species and 21 species of toothed whale (including at least 17 delphinid species).
• 3 Cetaceans could be broadly split into seven ecological categories, based on their distribution. A warm temperate/tropical deep‐water cetacean community dominated the study area. Cooler water from the Benguela Current influenced southern Angola (≤16°S latitude) and at least three cetacean species occurred predominantly in this region.
• 4 Only three or fewer species were confirmed in the waters of Togo, Nigeria, Cameroon and the Democratic Republic of Congo. Seventeen or more species were documented in Ghana, Gabon and Angola, where dedicated cetacean research projects have been initiated in recent years. Angola had the most diverse documented cetacean community: 28 confirmed species.
• 5 The humpback whale Megaptera novaeangliae was the most widely recorded species, and was documented in 11 (85%) countries. Sperm whales Physeter macrocephalus, Bryde's whales Balaenoptera cf. brydei, bottlenose dolphins Tursiops truncatus and Atlantic spotted dolphins Stenella frontalis were recorded in over half of the countries.

     

The oldest lamprophiid (Serpentes,Caenophidia) fossil from the late Oligocene Rukwa Rift Basin,Tanzania and the origins of African snake diversity

Extant snake faunas have their origins in the mid-Cenozoic, when colubroids replaced booid-grade snakes as the dominant species. The timing of this faunal changeover in North America and Europe based on fossils is thought to have occurred in the early Neogene, after a period of global cooling opened environments and made them suitable for more active predators. However, new fossils from the late Oligocene of Tanzania have revealed an early colubroid-dominated fauna in Africa suggesting a different pattern of faunal turnover there. Additionally, molecular divergence times suggest colubroid diversification began sometime in the Paleogene, although the exact timing and driving forces behind the diversification are not clear. Here we present the first fossil snake referred to the African clade Lamprophiinae, and the oldest fossil known of Lamprophiidae. As such, this specimen provides the only potential fossil calibration point for the African snake radiation represented by Lamprophiidae, and is the oldest snake referred to Elapoidea. A molecular clock analysis using this and other previously reported fossils as calibration points reveals colubroid diversification minimally occurred in the earliest Paleogene, although a Cretaceous origin cannot be excluded. The elapoid and colubrid lineages diverged during the period of global warming near the Paleocene-Eocene boundary, with both clades diversifying beginning in the early Eocene (proximate to the Early Eocene Climate Optimum) and continuing into the cooler Miocene. The majority of subclades diverge well before the appearance of colubroid dominance in the fossil record. These results suggest an earlier diversification of colubroids than generally previously thought, with hypothesized origins of these clades in Asia and Africa where the fossil record is relatively poorly known. Further work in these regions may provide new insights into the timing of, and environmental influences contributing to, the rise of colubroid snakes.     

Lithostratigraphic context of Oligocene mammalian faunas from Ulantatal,Nei Mongol,China

The Ulantatal area is well-known for its extraordinarily rich Oligocene mammalian fossils. The Ulantatal fauna was originally considered to be the representative fauna for the Chinese Land mammalian Age, Ulantatalian. However, the abundant fossils collected in the 1980s lack coordinates and/or detailed stratigraphic levels, and have been lumped together as either single, coeval fauna or grouped into three units. This lack of stratigraphic information hampers more precise biostratigraphic division and correlation of the faunas. Here we present a complete lithostratigraphic profile of the Ulantatal Formation with new fossil localities calibrated into the profile. Lithologically, the sequence shows a rather uniform pattern characterized by interbedded reddish to yellowish brown claystones and siltstones, with minor fine-grained sandstones. Preliminary biostratigraphic analysis shows that the Ulantatal Formation covers most of the Oligocene, and offers a long sequence and successive fossil records for understanding the evolution of mammal faunas after the critical Eocene/Oligocene transition.     

Enigmatic new mammals from the late Eocene of Egypt

A new mammalian genus and species from the earliest late Eocene of Egypt is represented by a lower jaw fragment and two isolated lower molars. A rare combination of features and the fragmentary nature of the materials make their taxonomic assignment to either Marsupialia or Chiroptera uncertain. The holotype of the new genus is the best-preserved specimen in the sample, a dentary fragment with two molars that have uncompressed trigonids, weak buccal cingulids, and a nyctalodont arrangement of the hypocristid. Some traits appear to more clearly support marsupial, as opposed to chiropteran, affinities for this species, including the very likely presence of four molars in the dentary. The enamel of an additional lower molar assigned to this species consists of a single layer of radial enamel without any prism decussation, an enamel type that characterizes marsupials as well as chiropterans. A second taxon is represented by two isolated upper molars. Some traits appear to more clearly support marsupial, as opposed to chiropteran, affinities for these species, including the orientation of pre- and postprotocristae, the moderately slender lingual portion of the trigon, and the absence of any talon expansion. As some of these features can be found in various bat clades, chiropteran affinities for these species cannot be ruled out, but we propose that the new taxa are more likely to represent specialized ‘didelphimorphian’ marsupials.      

A reassessment of the taxonomic and phylogenetic affinities of the fossil catarrhines from fort Ternan,Kenya

This paper presents a reassessment of the taxonomic and phylogenetic affinities of the fossil catarrhine primates from the important middle Miocene site of Fort Ternan in Kenya. Although the sample of specimens is rather small, the material can be attributed to at least five different species, identified here asKenyapithecus wickeri, Proconsul sp., a large species of oreopithecid,Simiolus sp., and a small species of catarrhine of indeterminate status.Kenyapithecus wickeri probably represents a conservative sister-taxon of the extant large hominoids. It is more derived than“Sivapithecus” africanus from Maboko Island, from which it can be distinguished at the generic level. A small species of catarrhine from Fort Ternan can be attributed toSimiolus. It is probably a different species fromSimiolus enjiessi from the early Miocene of East Africa, but additional material is needed to confirm its taxonomic distinctiveness. The occurrence of at least five species of catarrhine primates at Fort Ternan confirms that species diversity levels were as high during the middle Miocene as they had been during the early Miocene. However, the overall taxonomic and ecological composition of the middle Miocene catarrhine community was quite different, evidently due to a significant change in the local ecological setting. Taxonomic differences between the catarrhine faunas at Fort Ternan and Maboko Island can probably be explained as a consequence of a chronological separation between the two sites, and, to a lesser degree, to paleoecological differences.     

Paleobiogeography of Africa: How distinct from Gondwana and Laurasia?

Although Africa was south of the Tethys Sea and originally belonged to the Gondwana, its paleobiogeographical history appears to have been distinct from those of both Gondwana and Laurasia as early as the earliest Cretaceous, perhaps the Late Jurassic. This history has been more complex than the classical one reconstructed in the context of a dual world (Gondwana vs. Laurasia). Geological and paleobiogeographical data show that Africa was isolated from the Mid-Cretaceous (Albian-Aptian) to Early Miocene, i.e., for ca. 75 million years. The isolation of Africa was broken intermittently by discontinuous filter routes that linked it to some other Gondwanan continents (Madagascar, South America, and perhaps India), but mainly to Laurasia. Interchanges with Gondwana were rare and mainly “out-of-Africa” dispersals, whereas interchanges with Laurasia were numerous and bidirectional, although mainly from Laurasia to Africa. Despite these intermittent connections, isolation resulted in remarkable absences, poor diversity, and emergence of endemic taxa in Africa. Mammals suggest that an African faunal province might have appeared by Late Jurassic or earliest Cretaceous times, i.e., before the opening of the South Atlantic. During isolation, Africa was inhabited by vicariant West Gondwanan taxa (i.e., taxa inherited from the former South American-African block) that represent the African autochthonous forms, and by immigrants that entered Africa owing to filter routes. Nearly all, or all immigrants were of Laurasian origin. Trans-Tethyan dispersals between Africa and Laurasia were relatively frequent during the Cretaceous and Paleogene and are documented as early as the earliest Cretaceous or perhaps Late Jurassic, i.e., perhaps by the time of completion of the Tethys between Gondwana and Laurasia. They were permitted by the Mediterranean Tethyan Sill, a discontinuous route that connected Africa to Laurasia and was controlled by sea-level changes. Interchanges first took place between southwestern Europe and Africa, but by the Middle Eocene a second, eastern route — the Iranian route — involved southeastern Europe and southwestern Asia. The Iranian route was apparently the filtering precursor of the definitive connection between Africa and Eurasia. The relationships and successive immigrations of mammal (mostly placental) clades in Africa allow the recognition of five to seven phases of trans-Tethyan dispersals between Africa and Laurasia that range from the Late Cretaceous to the Eocene-Oligocene transition. These Dispersal Phases involve dispersals toward Laurasia and/or toward Africa (immigrations). The immigrations in Africa gave rise to faunal assemblages, the African Faunal Strata (AFSs). All successful and typical African radiations have arisen from these AFSs. We recognize four to six AFSs, each characterized by a faunal association. Even major, old African clades such as Paenungulata or the still controversial Afrotheria, which belong to the oldest known AFS involving placentals, ultimately originated from a Laurasian stem group. Africa was an important center of origin of various placental clades. Their success in Africa is probably related to peculiar African conditions (endemicity, weak competition). Although strongly marked by endemicity, the African placental fauna did not suffer extinctions of major clades when Africa contacted Eurasia. The present geographic configuration began to take shape as early as the Mid-Cretaceous. At that time, the last connections between Africa and other Gondwanan continents began to disappear, whereas Africa was already connected to Eurasia by a comparatively effective route of interchange.     

A biogeographical regionalization of Angolan mammals

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Talar morphology of azibiids, strepsirhine-related primates from the Eocene of Algeria: phylogenetic affinities and locomotor adaptation

The HGL-50 locality, situated on the Glib Zegdou outlier in the Gour Lazib of Algeria (Hammada du Dra), is famous for having yielded several dental remains of primates dating from the late Early to the early Middle Eocene. These primates include Algeripithecus minutus, Azibius trerki and a new species of cf. Azibius (not described yet). Algeripithecus was widely acknowledged to be one of the oldest known anthropoids from Africa. However, very recent discoveries strongly suggest that Algeripithecus is closely related to Azibius and that both taxa are phylogenetically remote from the clade Anthropoidea. Algeripithecus and Azibius make up the family Azibiidae and appear as stem strepsirhines. Here we describe and analyse two ankle bones (tali) found in HGL-50. UM/HGL50-466 is a small left talus, which is appropriate in size to belong to A. trerki, while UM/HGL50-467 is a right talus, which is significantly larger and appropriate in size to belong to the new large species of cf. Azibius. Both tali exhibit a suite of features that resemble conditions primarily found in extinct and extant strepsirhine and adapiform primates; conditions that are consistent with the strepsirhine-like dentition characterizing azibiids. Functionally, these two tali indicate that Azibius species were engaged in a form of active arboreal quadrupedalism with some ability to climb and leap. Azibiids were rather small-bodied primates, approximating the size of some modern dwarf lemurs (Cheirogaleidae) and sportive lemurs (Lepilemuridae) from Madagascar. Given their small body-size and their talar morphology, living cheirogaleid lemurs, which are agile arboreal quadrupeds (with climbing, springing and branch running activities), might appear as good analogues for azibiids in terms of locomotor behaviour.     

Afrotropical and Nearctic genera of Odonata in the French Oligocene: biogeographic and paleoclimatic implications (Insecta: Calopterygidae,Aeshnidae)

New species of the genera Sapho and Epiaeschna are recorded in the Oligocene of Aix- en-Provence, Bouches-du-Rhône, France. Sapho legrandi n. sp. is the third fossil representative of this recent African genus and Epiaeschna pseudoheros n. sp. is the fifth fossil species of this recent North American genus. The fossil species Triaeschna gossi from the Eocene of England, Epacantha magnifica from the Late Oligocene of Kazakhstan, and Mediaeschna matutina from the Oligocene of China, are considered species of Epiaeschna and the three fossil genera Triaeschna Campion 1916, Mediaeschna Zhang 1989, and Epacantha Martynov 1929 are synonymized with Epiaeschna. The closely related genera Umma and Sapho inhabit warm humid forests of Western Africa. Their presence in two Oligocene deposits of France supports the hypothesis of a warm humid palaeoenvironment for Armissan (Aude, France), and Aix-en-Provence.     

Developmental origins and homologies of the hyracoid dentition

Understanding the origins of morphological specializations in mammals is a key goal in evolutionary biology. It can be accomplished by studying dental homology, which is at the core of most evolutionary and developmental studies. Here, we focused on the evolution and development of the specialized dentition of hyraxes for which dental homologies have long been debated, and could have implications on early placental evolution. Specifically, we analysed dental mineralization sequences of the three living genera of hyraxes and 17 fossil species using X‐ray computed microtomography. Our results point out the labile position of vestigial upper teeth on jaw bones in extant species, associated with the frequently unusual premolar shape of deciduous canines over 50 Ma of hyracoid evolution. We proposed two evolutionary and developmental hypotheses to explain these original hyracoid dental characteristics. (a) The presence of a vestigial teeth on the maxilla in front of a complex deciduous canine could be interpreted as extra‐teeth reminiscent of early placental evolution or sirenians, an order phylogenetically close to hyracoids and showing five premolars. (b) These vestigial teeth could also correspond to third incisors with a position unusually shifted on the maxilla, which could be explained by the dual developmental origin of these most posterior incisors and their degenerated condition. This integrative study allows discussion on the current evolutionary and developmental paradigms associated with the mammalian dentition. It also highlights the importance of nonmodel species to understand dental homologies.     

A new genus of rodents (Remyidae, Mammalia) from the Iberian Eocene

Abstract:  In this article, a new genus, Frontanyamys , is defined based on the new species F. russelli . The genus is recorded from the lower Upper Eocene (Bartonian) beds AT Sant Jaume de Frontanya (NE Spain). This genus shows clear affinities with the previously described genera Zamoramys, Remys and Pairomys. They are therefore assembled in the family Remyidae (new rank). The remyids are characterised by the precocious development of high-crowned molars and retain a morphologically primitive dental pattern. The oldest remyids are found in the middle Eocene of Spain ( Zamoramys ) and are probably derived from a morphologically primitive protrogomorph rodent such as Corbarimys paisi . The last representatives of the family such as Remys and Pairomys developed a fully lophodont dental pattern.