[PaleoMammalogy • 2023] Phylogeny and Paleobiogeography of the enigmatic North American Primate Ekgmowechashala illuminated by New Fossils from Nebraska (USA) and Guangxi (China)

 

Ekgmowechashala 

in Rust, Ni, Tietjen & Beard, 2023. 

DOI: 10.1016/j.jhevol.2023.103452

Artwork: Kristen Tietjen

Abstract

Ekgmowechashala is a poorly documented but very distinctive primate known only from the late early Oligocene (early Arikareean) of western North America. Because of its highly autapomorphous dentition and spatiotemporal isolation, the phylogenetic and biogeographic affinities of Ekgmowechashala have long been debated. Here, we describe the oldest known fossils of Ekgmowechashala from the Brown Siltstone Beds of the Brule Formation, White River Group of western Nebraska. We also describe a new ekgmowechashaline taxon [Palaeohodites naduensis gen. nov. et sp. nov.] from the Nadu Formation (late Eocene) in the Baise Basin of Guangxi Zhuang Autonomous Region in southern China. Phylogenetic analysis suggests that North American Ekgmowechashala and the new Chinese taxon are sister taxa that are nested within a radiation of southern Asian adapiforms that also includes Gatanthropus, Muangthanhinius, and Bugtilemur. The new Chinese ekgmowechashaline helps fill the considerable disparity in dental morphology between Ekgmowechashala and more primitive ekgmowechashalids known from southern Asia. Our study underscores the fundamental role of southern Asia as a refugium for multiple primate clades during the cooler and drier climatic regime that prevailed after the Eocene–Oligocene transition. The colonization of North America by Ekgmowechashala helps define the beginning of the Arikareean Land Mammal Age and corresponds to an example of the Lazarus effect, whereby a taxon (in this case, the order Primates) reappears suddenly in the fossil record after a lengthy hiatus.

Keywords: Ekgmowechashalidae, Adapiformes, Eocene–Oligocene transition, Paleobiogeography, Dental evolution, Lazarus effect

Order Primates Linnaeus, 1758

Semiorder Strepsirrhini Geoffroy, 1812

Infraorder Adapiformes Hoffstetter, 1977

Family Ekgmowechashalidae Szalay, 1976

Included genera Ekgmowechashala Macdonald, 1963; 

Bugtilemur Marivaux et al., 2001; 

Muangthanhinius Marivaux et al., 2006; 

Gatanthropus Ni et al., 2016; 

Palaeohodites, gen. nov.

Subfamily Bugtilemurinae, subfam. nov.

Type genus Bugtilemur Marivaux et al., 2001.

Included genera Bugtilemur Marivaux et al., 2001; 

Muangthanhinius Marivaux et al., 2006.

Diagnosis Differs from Ekgmowechashalinae in lacking highly crenulated enamel; lacking multiple neomorphic cusps and cuspules on upper and lower molars, including those identified as duplicated metaconule, duplicated protocone, ectostylids, and metastylids; and lacking large conules on upper molars.

Subfamily Ekgmowechashalinae Szalay, 1976

Included genera Ekgmowechashala Macdonald, 1963; 

Palaeohodites, gen. nov.

Genus Ekgmowechashala Macdonald, 1963

Type species Ekgmowechashala philotau Macdonald, 1963.

Ekgmowechashala zancanellai Samuels et al., 2015.

Ekgmowechashala philotau Macdonald, 1963

 

 Upper molar morphology in ekgmowechashaline primates, highlighting similarities and differences between Ekgmowechashala philotau from the Gering Formation, Nebraska, USA, and Palaeohodites naduensis from the Nadu Formation, Baise Basin, Guangxi Zhuang Autonomous Region, China.
 A, B) Ekgmowechashala philotau, isolated right M2 (KUVP 69859) in occlusal (A) and lingual (B) views.
C, D) Palaeohodites naduensis, right maxillary fragment preserving M2 (IVPP V 32350) in occlusal (C) and lingual (D) views.

Genus Palaeohodites gen. nov.

Etymology Combination of the Greek words palaios (ancient, old) and hodites (wanderer).

Type species Palaeohodites naduensis sp. nov.

Diagnosis Differs from Ekgmowechashala in having relatively longer and narrower P2–3, P2 roots more widely spaced, M1 with vestigial paraconid and large neomorphic cusp on central part of postvallid, M1–2 with hypoconid and hypoconulid clearly separate and cuspidate, and M2 without a continuous centrocrista and with closely connate lingual cusps. Differs from Gatanthropus and bugtilemurines in having heavily crenulated enamel, multiple neomorphic lower molar cusps, and duplicated protocone and inflated conules on M2.

Palaeohodites naduensis sp. nov.

Type locality Outcrop of the Nadu Formation located ∼1.5 km northeast of Quelin village, north-central Baise Basin, Guangxi Zhuang Autonomous Region, China (Fig. 2).

Age and distribution Late Eocene of the Baise Basin, Guangxi Zhuang Autonomous Region, China.

Etymology Named for the Nadu Formation, strata of which have yielded all known specimens of this species.

Illustration of Ekgmowechashala, the last primate to inhabit North America before humans.

Artwork: Kristen Tietjen, scientific illustrator with the KU Biodiversity Institute and Natural History Museum.

 Kathleen Rust, Xijun Ni, Kristen Tietjen and K. Christopher Beard. 2023. Phylogeny and Paleobiogeography of the enigmatic North American Primate Ekgmowechashala illuminated by New Fossils from Nebraska (USA) and Guangxi Zhuang Autonomous Region (China). Journal of Human Evolution. In Press, 103452. DOI: 10.1016/j.jhevol.2023.103452

  phys.org/news/2023-11-fossils-tale-primate-inhabit-north.html

[Mammalogy • 2022] Xanthonycticebus pygmaeus • A New Genus Name for Pygmy Lorises (Primates: Lorisidae)

Xanthonycticebus pygmaeus (Bonhote, 1907)

Photograph of wild adult male X. pygmaeus from Mondulkiri District, Cambodia and skull from Li Chau, Vietnam (FMNH 32499), compared with Nycticebus javanicus from Garut Regency, Indonesia and skull (RMNH14563) from South Java, Indonesia; and with Loris lydekkerianus nordicus from Trincomalee District, Sri Lanka and skull (FMNH95029) from Jaffna District, Sri Lanka.
Features distinctive to Xanthonycticebus include yellowish-orange colour, mid-broad snout with long premaxilla, M2 larger than M1 and ears hairless at the tips

 in Nekaris & Nijman, 2022.

DOI: 10.3897/zse.98.81942

 twitter.com/littlefireface 

Abstract

Lorisiformes are nocturnal primates from Africa and Asia with four genera, with two (Arctocebus and Loris), three (Perodicticus) and nine (Nycticebus) recognised species. Their cryptic lifestyle and lack of study have resulted in an underappreciation of the variation at the species and genus level. There are marked differences between the pygmy slow loris Nycticebus pygmaeus and the other Nycticebus species and, in the past, several authors have suggested that these may warrant recognition at the generic level. We here combine morphological, behavioural, karyotypical and genetic data to show that these contrasts are, indeed, significantly large and consistent. We propose Xanthonycticebus gen. nov. as a new genus name for the pygmy slow lorises and suggest a common name of pygmy lorises. Based on analysis of complete mitochondrial DNA sequences, we calculate the divergence of pygmy from slow lorises at 9.9–10.0%. The median date, calculated for the divergence between Xanthonycticebus and Nycticebus, is 10.5 Mya (range 4.9–21.0 Mya). Xanthonycticebus differs from Nycticebus by showing sympatry with other slow loris species, by habitually giving birth to twins, by showing seasonal body mass and whole body coat colour changes (absent in other species living at similar latitudes) and a multi-male, multi-female social system. Pygmy lorises are easily recognisable by the absence of hair on their ears and more protruding premaxilla. Xanthonycticebus is threatened by habitat loss and illegal trade despite legal protection across their range and all slow lorises are listed on appendix 1 of CITES. The suggested nomenclatural changes should not affect their legal status.

Key Words: conservation, cytotaxonomy, Lorisidae, Lorisiformes, primate taxonomy, Strepsirrhini

Order Primates Linnaeus, 1758

Suborder Strepsirhini É. Geoffroy Saint-Hilaire, 1812

Family Lorisidae Gray, 1821

Xanthonycticebus gen. nov.

Xanthonycticebus pygmaeus (Bonhote, 1907)

syn: Nycticebus pygmaeus Bonhote, 1907

Characteristics of pygmy loris Xanthonycticebus pygmaeus gen. nov. 

A. Photograph of wild adult male X. pygmaeus from Mondulkiri District, Cambodia and skull from Li Chau, Vietnam (FMNH 32499), compared with Nycticebus javanicus from Garut Regency, Indonesia and skull (RMNH14563) from South Java, Indonesia; and with Loris lydekkerianus nordicus from Trincomalee District, Sri Lanka and skull (FMNH95029) from Jaffna District, Sri Lanka. Features distinctive to Xanthonycticebus include yellowish-orange colour, mid-broad snout with long premaxilla, M2 larger than M1 and ears hairless at the tips; 

B. Neighbour-joining tree of 175 cytochrome b sequences (alignment 1,068 bp) of Nycticebus, Xanthonycticebus and Loris; 

C. Neighbour-joining tree of complete mtDNA sequences of Nycticebus, Xanthonycticebus and Loris, with Perodicticus as outgroup, showing considerable divergence of Xanthonycticebus from Nycticebus. 

All photographs courtesy of K.A.I. Nekaris.

Photograph of wild adult male  Xanthonycticebus pygmaeus from Mondulkiri District, Cambodia and skull from Li Chau, Vietnam (FMNH 32499),
compared with Nycticebus javanicus from Garut Regency, Indonesia and skull (RMNH14563) from South Java, Indonesia;
and with Loris lydekkerianus nordicus from Trincomalee District, Sri Lanka and skull (FMNH95029) from Jaffna District, Sri Lanka.
Features distinctive to Xanthonycticebus include yellowish-orange colour, mid-broad snout with long premaxilla, M2 larger than M1 and ears hairless at the tips.

    

 

Diagnosis: Morphological synapomorphies to Xanthonycticebus include: (i) skull length consistently less than 55 mm, (ii) diastema between P2 and P3, (iii) long black ears, hairless at the tips (iv) relatively narrow interorbital distance compared to Nycticebus and (v) full seasonal coat colour change including almost complete loss of dorsal stripe (Fig. 1). The species is furthermore distinguished from Nycticebus species by giving birth habitually to twins, frequent sympatry with N. bengalensis (sensu lato) and more rapid locomotion. Regarding multiple births, this trait occurs with varying frequency in primates. Most of the marmosets and tamarins are polyovulatory and twins are the dominant litter size in the wild and most twins are considered dizygotic (Ward et al. 2014; Wahab et al. 2015). Old World monkeys, apes and humans are monovulatory species and while single births are the rule, multiple births do occasionally occur in various species, typically at a rate at, or below one percent (Geissmann 1990). Around two-thirds to three-quarters of these twins are estimated to be monozygotic (Geissmann 1990). This contrasts with twinning in strepsirrhines, as here all, or practically all, are dizygotic (Pasztor and Van Horn 1979). No other species of slow lorises are known to be sympatric, with their distribution similar to gibbons Hylobatidae Gray, 1870 and langurs Presbytina Gray, 1825, which, even though having more recent evolutionary histories, contain multiple genera (Rowe and Meyers 2016). Where nocturnal primate genera or species are sympatric, different locomotor strategies have evolved, allowing reduced competition (Charles-Dominique 1977). Additional differences, as well as those from Loris, are summarised in Table 1.

Etymology: The genus name Xanthonycticebus, masculine, refers to the species orange/ish overall colouration and their nocturnal activity pattern; Xanto, Gr. Yellowish-orange; nykt-, Gr., night; kêbos, Gr., monkey (Gainsford 2020). Currently, the most frequently used common name of this genus is pygmy slow loris, followed by the rarely used lesser slow loris or intermediary slow loris. For the common English name, we suggest pygmy loris in order to differentiate the new genus from the two other loris genera (slow and slender lorises). We acknowledge, however, that with the recognition of N. menagensis Munds, Nekaris and Ford 2013, from Borneo, with a minimum adult body mass of 265 g, the small size is no longer a unique feature of the pygmy loris. 

The most commonly-used name for pygmy lorises in Vietnamese is Cu li nhỏ, in Mnong, it is Tau kless, in Lao, it is Linh lom and in Chinese, it is 小懶猴 / Xiǎo lǎn hóu (Nijman and Nekaris 2016;Thạch et al. 2018).

K. Anne-Isola Nekaris and Vincent Nijman. 2022. A New Genus Name for Pygmy Lorises, Xanthonycticebus gen. nov. (Mammalia, Primates). Zoosystematics and Evolution. 98(1); 87-92. DOI: 10.3897/zse.98.81942

 twitter.com/littlefireface/status/1506932825152532487

[Mammalogy • 2017] Paragalago gen. nov. • A New Genus for the eastern Dwarf Galagos (Primates: Galagidae)

Abstract

The family Galagidae (African galagos or bushbabies) comprises five genera: Euoticus Gray, 1872; Galago Geoffroy Saint-Hilaire, 1796; Galagoides Smith, 1833; Otolemur Coquerel, 1859; and Sciurocheirus Gray, 1872, none of which is regarded as monotypic, but some (Euoticus and Otolemur) certainly qualify as oligotypic. We argue for the recognition of a sixth genus, if the taxonomy is to reflect galagid evolution accurately. Genetic evidence has consistently demonstrated that the taxa currently referred to the genus Galagoides are not monophyletic but form two clades (a western and an eastern clade) that do not share an exclusive common ancestor; we review 20 years of genetic studies that corroborate this conclusion. Further, we compare vocalizations emitted by small-bodied galagids with proposed phylogenetic relationships and demonstrate congruence between these data sets. Morphological evidence, however, is not entirely congruent with genetic reconstructions; parallel dwarfing in the two clades has led to convergences in skull size and shape that have complicated the classification of the smaller species. We present a craniodental morphometric analysis of small-bodied galagid genera that identifies distinguishing characters for the genera and supports our proposal that five taxa currently subsumed under Galagoides (Galagoides cocos, Galagoides granti, Galagoides orinus, Galagoides rondoensis and Galagoides zanzibaricus) be placed in their own genus, for which we propose the name Paragalago.

Keywords: Biogeography, Bushbaby, Craniodental Morphometrics, Galagoides, Molecular Phylogeny, Paragalago, Vocalizations.

Map showing approximate geographic ranges of the two independent dwarf galago clades, Galagoides (red) and the eastern dwarf galagos [Paragalago] (blue). The type localities of the species comprising the genera are indicated by symbols. In the case of Galagoides demidoff, the type locality is estimated from Fischer’s (1806) description. 

A Kenya coast galago (Paragalago cocos).

Photo: Luca Pozzi

Judith C. Masters, Fabien Génin, Sébastien Couette, Colin P. Groves, Stephen D. Nash, Massimiliano Delpero and Luca Pozzi. 2017. A New Genus for the eastern Dwarf Galagos (Primates: Galagidae). Zool J Linn Soc. zlw028. DOI:  10.1093/zoolinnean/zlw028

twitter.com/LPozzi81/status/829722600515461120

African bush babies gain a new genus https://news.mongabay.com/2017/02/african-bush-babies-gain-a-new-genus/ via @mongabay

[Mammalogy • 2017] Galagoides kumbirensis • A Giant Among Dwarfs: A New Species of Galago (Primates: Galagidae) from Angola

Galagoides kumbirensis 

Svensson, Bersacola, Mills, Munds, Nijman, Perkin, Masters, Couette, Nekaris & Bearder. 2017

DOI: 10.1002/ajpa.23175  

Abstract

Objectives

Based on vocalization recordings of an unknown galago species, our main objectives were to compare morphology and call structure with known closely-related taxa and describe a new species of galago.

Materials and methods

We conducted field surveys in three forest habitats along the escarpment region in western Angola (Kumbira Forest, Bimbe Area, and Northern Scarp Forest), and examined galago specimens from museums worldwide. We digitized and analyzed calls using Avisoft SASLab Pro software. We also compared museum specimens from Angola with other Galago and Galagoides specimens, and conducted comparative analyses (ANOVA and between group principle component analysis) based on a set of twelve linear measurements of skulls and teeth.

Results

We describe the new species to which we give the name Angolan dwarf galago, Galagoides kumbirensis sp. nov. The new species has a loud and characteristic crescendo call, used by other Galagoides spp. (sensu stricto) in West Africa to attract companions and repel rivals. However, this call shows species-typical differences from its closest relatives. Galagoides kumbirensis sp. nov. is also distinguished by differences in the skull morphology, pelage color and facial markings, as well as a larger body size, similar to that of Galago moholi, which is not known to be sympatric.

Conclusion

This discovery points to the importance of Angolan forests as refuges for endemic biodiversity. These forests are under severe threat from overexploitation, and there is an urgent need to establish conservation measures and designate protected areas.

KEYWORDS: Bushbaby, cryptic species, Galagoides, morphology, strepsirrhine

FIGURE 2 (A, B) Skin and skull of one of the syntypes of Galagoides kumbirensis sp. nov. (FMHN 81756);
(C) paratype (in situ Kumbira Forest) 

Etymology: The species was first observed in situ in Kumbira Forest, an area undergreat pressure from commercial logging (Bersacola et al., 2015; Cáceres et al., 2016). Kumbira is considered a hotspot for many endemic species in Angola (Cáceres et al., 2015) and by using this name we aim to draw attention to the area.  

Suggested common name: Angolan dwarf galago (English), galago angolano (Portuguese)

 Magdalena S. Svensson, Elena Bersacola, Michael S. L. Mills, Rachel A. Munds, Vincent Nijman, Andrew Perkin, Judith C. Masters, Sébastien Couette, K. Anne-Isola Nekaris and Simon K. Bearder. 2017.  A Giant Among Dwarfs: A New Species of Galago (Primates: Galagidae) from Angola.  American Journal of Physical Anthropology. DOI: 10.1002/ajpa.23175 ResearchGate.net/publication/313882784_A_giant_among_dwarfs_a_new_species_of_galago_Primates_Galagidae_from_Angola

This new primate is a ‘giant’ among tiny bush babies https://news.mongabay.com/2017/02/this-new-primate-is-a-giant-among-tiny-bushbabies/ via  @mongabay

New species of bushbaby found in disappearing forests of Angola https://www.newscientist.com/article/2121970-new-species-of-bushbaby-found-in-disappearing-forests-of-angola

[Primatology • 2016] Cheirogaleus shethi • A New Species of Dwarf Lemur (Cheirogaleidae: Cheirogaleus medius Group) from the Ankarana and Andrafiamena-Andavakoera Massifs, Madagascar

Ankarana or Sheth’s Dwarf Lemur  |  Cheirogaleus shethi 

Frasier, Lei, McLain, Taylor, Bailey, Ginter, Nash,
Randriamampionona, Groves, Mittermeier & Louis, 2016

Abstract

A new species of dwarf lemur, Cheirogaleus shethi sp. nov., of the C. medius group is described from the dry and transitional forests of northern Madagascar. This species can be found along the forest corridor from Ankarana Special Reserve east to the Analamerana Special Reserve down to the Bekaraoka forest in the Loky-Manambato Protected Area. This species is genetically distinct from other members of the C. medius species group and is sister to a poorly known lineage in Sambava. The identification of this new species highlights the importance of northern Madagascar as a reservoir of biodiversity.

Key Words: Dwarf lemurs, primate, Strepsirrhini, taxonomy

Figure 5. Illustration of Cheirogaleus shethi (Stephen D. Nash © Conservation International) and
photographs of KAR15.1 taken at Ankarana Special Reserve (photos by Richard Randriamampionona). 

Cheirogaleus shethi

Formerly Cheirogaleus sp. nov. 4, also CCS6 (Lei et al. 2014);
 in part C. sp. Bekaraoka Sambava (Thiele et al. 2013).

Distribution: Known from northern Madagascar, from Ankarana east to Bekaraoka in dry and transitional forests. Found in the Ankarana Special Reserve, Andrafiamena-Andavakoera Protected Area, Analamerana Special Reserve, and Loky-Manambato Protected Area. 

Etymology: This new species is named after Brian Sheth, the Chair of the Board of the NGO Global Wildlife Conservation. Brian is deeply committed to biodiversity conservation worldwide, and is a leading philanthropist for species and ecosystem conservation. He has supported many projects in Madagascar, including research and the establishment and management of nature reserves. His passion and drive to help save the diversity of life on our planet has been an inspiration to all around him. 

Vernacular names: Ankarana or Sheth’s Dwarf Lemur.

Figure 4. Map of Madagascar with the ranges of Cheirogaleus sp. nov. 4 and closely related Cheirogaleus species highlighted to show the geographic distance between lineages. Identification numbers on the map correspond to ID numbers of animals listed in Table 1. Photographs of C. andysabini and C. sp. nov. 4 are provided to show a clear difference in pelage and the distance between the ranges of the two lineages from different species groups. 

Cynthia L. Frasier, Runhua Lei, Adam T. McLain, Justin M. Taylor, Carolyn A. Bailey, Azure L. Ginter, Stephen D. Nash, Richard Randriamampionona, Colin P. Groves, Russell A. Mittermeier and Edward E. Louis Jr. 2016. A New Species of Dwarf Lemur (Cheirogaleidae: Cheirogaleus medius Group) from the Ankarana and Andrafiamena-Andavakoera Massifs, Madagascar.   Primate Conservation. (30); 59–72.   

http://static1.1.sqspcdn.com/static/f/1200343/27358083/1480545032610/PC30_Frasier_et_al_Cheirogaleus_shethi.pdf?token=SRINo0un7v1IwIAooUv39tSF%2FIs%3D
ResearchGate.net/publication/311848011_A_New_Species_of_Dwarf_Lemur_Cheirogaleidae_Cheirogaleus_medius_Group_from_the_Ankarana_and_Andrafiamena-Andavakoera_Massifs_Madagascar

Stare into the Soulful Eyes of This Newly Discovered Dwarf Lemur Species https://blogs.scientificamerican.com/extinction-countdown/stare-into-the-soulful-eyes-of-this-newly-discovered-dwarf-lemur-species/

https://madagascarpartnership.org/2016/12/22/newly-identified-lemur-species/