2020 in mammal paleontology

General research

• A study on the phylogenetic relationships of the haramiyidans and on the consistency between the known morphology and age of Juramaia and other mammaliaforms from the Yanliao Biota, as indicated by Bayesian tip-dated phylogenetic methods, is published by King & Beck.
• A study aiming to determine resource and habitat use, niche occupation and trophic interactions of mammals living during the Great American Interchange, as indicated by carbon and oxygen stable isotope compositions of tooth enamel of fossil mammals from the late Miocene to the late Pleistocene of the Pampean region of Argentina, is published by Domingo et al..
• A study on predator richness in mammalian communities from the Miocene Santa Cruz Formation, aiming to determine whether the mammalian predator guild from this area was impoverished prior to the Great American Interchange, is published by Rodríguez-Gómez et al..

  Metatherians

• A study comparing the anatomy of the skull and teeth of Thylacosmilus atrox and placental saber-toothed carnivores is published by Janis et al., who question the interpretation of T. atrox as having a similar type of predatory behavior to placental saber-tooths, and consider it unlikely that T. atrox used its canines to dispatch its prey.
• A study on the anatomy of the petrosal and inner ear of Peratherium elegans and Amphiperatherium elegans, and on its implications for the knowledge of the phylogenetic relationships of herpetotheriids and peradectids, is published online by Ladevèze, Selva & de Muizon.
• A study on the anatomy of the teeth of Groeberia, and on the phylogenetic affinities of this genus, is published by Zimicz & Goin.
• A study on the relationship between variation in skull and mandibular shape of extant and extinct macropodiforms and ecological factors such as diet, locomotion and body mass, and on the implications of this relationship for the knowledge of the feeding ecology of the fossil macropodiforms from the Riversleigh World Heritage Area, is published online by Butler et al..
• A study on the morphology of the humeri of fossil kangaroos belonging to the subfamily Sthenurinae and of Protemnodon, evaluating its implications for the knowledge of the mode of locomotion in these marsupials, is published online by Janis et al..
• The hypothesis that marsupial forelimbs are restricted by long-term developmental constraints resulting from their reproductive strategy, is challenged in a paper to be published by Martin-Serra and Benson.

Eutherians

• A review of the origins, evolution and paleoecology of major clades of extinct native South American ungulates is published by Croft, Gelfo & López.
• A study on zinc isotope ratios in tooth enamel of Late Pleistocene mammals from the Tam Hay Marklot cave is published by Bourgon et al., who evaluate potential utility of zinc isotopes as dietary tracers in paleontology and archeology.

  Xenarthrans

• A metacarpal of a member of Xenarthra of uncertain phylogenetic placement is reported from the Eocene La Meseta Formation by Davis et al., supporting previously controversial reports of Xenarthra from Antarctica.
• A study on an assemblage of at least 22 specimens of Eremotherium laurillardi from the Pleistocene locality Tanque Loma is published by Lindsey et al., who interpret this assemblage as likely resulting from a mass mortality event, and evaluate its implications for the knowledge of the ecology of ground sloths.
• A study on the external and internal anatomy of the skull of Catonyx tarijensis is published by Boscaini et al..
• A study on a late Pleistocene assemblage of several individuals of Lestodon armatus from Playa del Barco site, aiming to determine the origin of this assemblage and its implications for the knowledge of the biology of L. armatus, is published by Tomassini et al..

Afrotherians

• A study on dietary differences among Pleistocene proboscideans in North America, and their implications for the knowledge of the causes of extinction of Cuvieronius, is published by Smith & DeSantis.
• Evidence of dietary resource partitioning among three proboscidean taxa from the early Pliocene locality of Langebaanweg in South Africa is presented by Groenewald et al..
• A study on the morphology of teeth and mandible of Serridentinus gobiensis and Miomastodon tongxinensis, as well as on the phylogenetic affinities of these taxa, is published by Wang, Zhang & Li, who reestablish Miomastodon as a genus distinct from Zygolophodon, and transfer S. gobiensis to the genus Miomastodon.

Bats

Notoungulates

Odd-toed ungulates

• A study comparing changes of body mass of ungulates belonging to the genera Lophiodon and Propalaeotherium from the middle Eocene site of Geiseltal is published by Ring et al..
• A study on the diet of lophialetid tapiroids from the Eocene of the Erlian Basin, as indicated by tooth wear, is published online by Gong et al..
• Iurino et al. describe the braincase with a natural brain endocast of a 12–18 months old rhinocerotine rhinoceros from the Middle Pleistocene site of Melpignano.
• Revision of the fossil material of hipparionines from the Miocene locality of Tizi N’Tadderht is published by Cirilli et al..
• Catalano et al. reconstruct a near complete mitogenome of a specimen of Equus hydruntinus from San Teodoro Cave, and evaluate the implications of their findings for the knowledge of the phylogenetic relationships of this taxon.

Even-toed ungulates

• New sample of isolated fossil auditory ossicles of cainotheriids is reported from the Paleogene karstic infillings of Dams by Assemat et al., who provide the first description of a reconstructed ossicular chain of Caenomeryx filholi.
• A study on the Old World fossil record of the family Camelidae, aiming to determine the timing of the divergence between the Bactrian camel and the dromedary, is published by Geraads et al..
• A study on the systematic relationships of extant and fossil members of the family Cervidae is published by Heckeberg.
• Description of new fossil bovid material from Xishuigou and a revision of the type material of "Eotragus" halamagaiensis from the Halamagai Formation is published by Li et al., who transfer "E." halamagaiensis to the genus Turcocerus.
• A study on the anatomy of molars of extant and fossil suids, and on its implications for reconstructions of diets of fossil suids from the Plio‐Pleistocene Turkana Basin, is published by Rannikko et al..
• A study comparing the distribution of ecomorphologies in the artiodactyl communities of North American Neogene savannas and modern-day African savannas is published by Morales-García, Säilä & Janis.

Cetaceans

• A study on the evolution of asymmetry in the skulls of living and extinct cetaceans is published by Coombs et al..

Carnivorans

• A study on changes in hindlimb functional diversity in North American carnivoran communities over the last 19 million years is published by Polly.
• Description of the tarsal bones of the bear dogs from the Paleogene of Europe, and a study on the evolution of posture and locomotion of European bear dogs, is published by Fournier et al..
• New fossil material of Megamphicyon giganteus, providing new information on the locomotor adaptations of this species and allowing an estimation of its body mass, is described from the middle Miocene site of Carpetana by Siliceo et al..
• A study on the anatomy of the holotype specimen of Vulpes alopecoides and on the diversity of the Plio-Pleistocene members of the genus Vulpes from Europe is published by Bartolini Lucenti & Madurell-Malapeira, who consider the species Vulpes praeglacialis and V. praecorsac to be junior synonyms of V. alopecoides.
• A study on the anatomy and likely diet of "Canis" ferox is published online by Bartolini Lucenti & Rook, who transfer this species to the genus Eucyon.
• A study comparing the anatomy of hyoid bones of dire wolves and coyotes from La Brea Tar Pits with those of extant canids, and evaluating the implications of reported anatomical differences for the knowledge of likely vocalizations of fossil canids, is published by Flores et al..
• The study of the extensive record of Canis from Dmanisi showed the combination so primitive and derived species that contrast with the previous interpretation of these specimens to Canis etruscus and support the description of the new species Canis borjgali, very close to Canis mosbachensis and probably to modern wolves, coyotes and affine dogs
• A study on the genomes of modern Greenland sled dogs, an ~9500-year-old Siberian dog associated with archaeological evidence for sled technology, and an ~33,000-year-old Siberian wolf is published by Sinding et al., who interpret their findings as indicating that sled dogs represent an ancient lineage going back at least 9500 years and that wolves bred with the ancestors of sled dogs and precontact American dogs.
• New specimen of Agnotherium antiquum, providing new information on the anatomy of this species, is described from the Miocene locality of Eppelsheim by Morlo et al., who interpret this species as a powerful, strictly carnivorous ambush hunter.
• A study on anatomical specializations in cave bears for longer hibernation periods, and on their impact on feeding biomechanics in cave bears, is published by Pérez-Ramos et al..
• A study on the diet of cave bears from cave sites in Romania, as indicated by nitrogen isotope values of individual amino acids from fossil collagen, is published by Naito et al..
• Description of new fossils and a review of the fossil material of large mustelids Sivaonyx hendeyi and Plesiogulo aff. monspessulanus from the Pliocene of the Langebaanweg fossil site is published by Valenciano & Govender.
• A study on the phylogenetic relationships of extant and fossil pinnipeds is published by Paterson et al..
• Rule, Hocking & Fitzgerald describe a tooth of a monachine seal from the Pliocene Whalers Bluff Formation, and evaluate its implications for the knowledge of the timing of pinniped faunal turnovers in the Southern Hemisphere.
• A study on the evolutionary history of the genus Crocuta, based on paleogenomic data from Late Pleistocene cave hyenas from across Eurasia and on population-level genomic data from sub-Saharan spotted hyenas, is published by Westbury et al..
• Description of a skull of Machairodus giganteus from the late Miocene locality Hadjidimovo, and a study on the evolution of the genus Machairodus, is published by Geraads & Spassov.
• An almost complete skull of Smilodon populator, likely belonging to one of the largest known specimens of the genus with an estimated body mass over 400 kg, is described from the Lujanian Dolores Formation by Manzuetti et al..
• A study on the evolutionary history of the cave lion, based on data from mitochondrial genomes of cave lions from across their entire prehistoric range, is published by Stanton et al..
• A study on the evolutionary history of lions, based on whole-genome resequencing data from a set of modern, historic, and Pleistocene lions, is published by de Manuel et al..

Rodents

• A study on brain anatomy and size in Neoepiblema acreensis is published by Ferreira et al..
• A study on a specimen of Ischyromys douglassi from the White River Formation of West Canyon Creek, representing the oldest and most complete articulated skeleton yet known of Ischyromys, is published by Rankin, Emry & Asher, who report that this specimen exhibits anatomical sciuromorphy, and evaluate its implications for the knowledge of jaw musculature evolution in rodents.
• A study on the morphology of the skull of the endemic dormouse Leithia melitensis from the Pleistocene of Sicily is published by Hennekam et al., who present a composite digital model of the skull of this rodent.
• Partial mitochondrial genome of the extinct beaver Castoroides is reported by Xenikoudakis et al., who evaluate the implications of this finding for the knowledge of the origin of aquatic behavior of beavers.
• A study on the anatomy and phylogenetic relationships of Megaoryzomys curioi is published by Ronez et al..
• A study aiming to determine whether insularity might have affected bone metabolism in Late Quaternary murine rodents from Timor is published by Miszkiewicz et al..

Primates

• A study aiming to determine whether the relationship between primate brain size and brain shape is characterized by allometry, and whether any such relationship may reflect shared macroevolutionary trends in primate brain shape, based on data from extant and four fossil primates, is published by Sansalone et al..
• Marigó et al. describe navicular bones of Anchomomys frontanyensis from the Eocene fossil site of Sant Jaume de Frontanyà-3C, representing first known navicular bones of an Eocene euprimate from Europe, and evaluate the implications of these fossils for the knowledge of early patterns of locomotor evolution in primates.
• Virtual endocast of a specimen of Necrolemur antiquus is presented by Harrington, Yapuncich & Boyer, who compare the endocast morphology of N. antiquus with those of other Eocene primates.
• A study on the anatomy of the talus of Paralouatta marianae and P. varonai, evaluating its implications for the knowledge of the locomotor behaviors of these primate, is published by Püschel et al..
• A study on the evolution of the vestibular apparatus in hominoids and on the utility of the study of the inner ear morphology for reconstructions of phylogenetic relationships of fossil apes, based on data from extant anthropoids and two fossil taxa, is published by Urciuoli et al..
• A study on the biomechanical performance of the patella of Pierolapithecus catalaunicus is published by Pina et al..
• A study on the ecology of fossil hominins and co-existing primates in the Turkana Basin area, based on data from tooth enamel stable calcium isotope values, is published by Martin et al..

  General paleoanthropology

• A study on the impact caused by hard plant tissues in contact with tooth enamel is published by van Casteren et al., who evaluate the implications of their findings for the knowledge of the diet of early hominins.
• A study on the mandible morphology, chewing biomechanics and probable diet of early hominins is published by Marcé-Nogué et al..
• A study on metacarpal trabecular and cortical bone in early hominins, and on its implications for the knowledge of diversity in hominin hand use, is published by Dunmore et al..
• A study on the phalangeal curvature of a chimpanzee who was raised during the 1930s to live much like a human, having very few opportunities to engage in arboreal activities, is published by Wallace, Burgess & Patel, who attempt to determine the extent to which phalangeal curvature is shaped by arboreal locomotion during life relative to genetic factors, and evaluate the implications of their findings for the interpretations of phalangeal curvature among fossil hominins.
• A study on the evolution of human brain size, shape, and asymmetry, based on data from apes and from species belonging to the genus Homo, is published by Melchionna et al., who report evidence indicating a significant shift in the rate of brain shape evolution in the clade including modern humans, Neanderthals and Homo heidelbergensis.
• Two hominin skulls, representing the earliest definitive occurrence of Paranthropus robustus and the earliest occurrence of a cranium with clear affinities to Homo erectus reported so far, are described from Drimolen by Herries et al., who interpret their findings as evidence that Homo, Paranthropus and Australopithecus were contemporaneous at ~2 million years ago.
• A study on the locomotion of two hominins from the Sterkfontein Caves in South Africa, testing for evidence of committed terrestrial bipedalism and for significant bouts of climbing, is published by Georgiou et al..
• A study on the maturational pattern of Paranthropus robustus, based on data from fossils from the Kromdraai B cave site, is published by Cazenave et al., who report evidence indicating that P. robustus had a maturational pattern that more closely approached the extant ape rather than the human condition.
• Richmond et al. report the first associated hand and upper limb skeleton of Paranthropus boisei from the Ileret site.
• A study aiming to determine the length of the Achilles tendon in Australopithecus is published by McNutt & DeSilva.
• A study on the anatomy of the atlas of the Australopithecus specimen Stw 573 and an additional Australopithecus specimen StW 679 from the Sterkfontein Member 4.
• A study on brain organization and growth in Australopithecus afarensis is published by Gunz et al..
• A 1.4-million-y-old large bone fragment shaped into handaxe-like form is described from the Konso Formation by Sano et al., expanding the documented technological repertoire of African Early Pleistocene Homo.
• An assemblage of immature remains of Homo naledi, including the first partial skeleton of a juvenile member of this species, is reported from the Dinaledi Chamber of the Rising Star Cave by Bolter et al..
• Bolter & Cameron utilize the methods used to study human growth and development for the reconstruction of ontogeny of Homo naledi.
• A study on the timing of the first appearance of Homo erectus at the Sangiran site is published by Matsu’ura et al..
• Semaw et al. report the discovery of crania of Homo erectus and both Acheulean and Oldowan artifacts at the Busidima North and Dana Aoule North sites, and interpret these findings as evidence of behavioral diversity and flexibility of H. erectus.
• Reconstruction of the thorax of the juvenile H. erectus skeleton KNM-WT 15000 from Nariokotome is presented by Bastir et al., who evalute the implications of the anatomy of this individual for the knowledge of the evolution of the modern human body shape.
• Welker et al. present tooth enamel proteomes of Homo antecessor from Atapuerca and Homo erectus from Dmanisi, and evaluate the implications of their findings for the knowledge of the phylogenetic placement of H. antecessor.
• A study on tooth enamel development in hominins from the paleontological sites of the Atapuerca complex, aiming to determine whether the Atapuerca hominins shared a suite or pattern of dental developmental characteristics with Homo sapiens, is published by Modesto-Mata et al..
• A study on the age of the Kabwe 1 skull from Broken Hill, and on its implications for the knowledge of human evolution, is published by Grün et al..
• Evidence of interbreeding between common ancestors of Neanderthals and Denisovans with a different hominin population that separated from other humans about 2 million years ago is presented by Rogers, Harris & Achenbach.
• A study on the exploitation of bivalves by Neanderthals from the Moscerini cave site is published by Villa et al., who report evidence indicating that Neanderthals collected aquatic resources by skin diving.
• Zilhão et al. present evidence from the Figueira Brava site on the Atlantic coast of Portugal indicating that Middle Paleolithic Neanderthals from this site exploited marine resources at a scale on par with the modern human–associated Middle Stone Age of southern Africa.
• A study on an assemblage of Neanderthal remains and Middle Paleolithic artifacts from the Chagyrskaya Cave is published by Kolobova et al., who compare this assemblage with other Altai sites, and interpret their findings as evidence of at least two Neanderthal incursions into southern Siberia.
• A high-quality genome of a Neanderthal from the Chagyrskaya Cave is sequenced by Mafessoni et al., who interpret the data from the genes expressed in the striatum of the brain as indicating that the striatum may have evolved unique functions in Neanderthals.
• Evidence of use of fibre technology by Neanderthals is reported from the Abri du Maras site by Hardy et al., who evaluate the implications of this finding for the knowledge of cognitive abilities of Neanderthals.
• Evidence of stable climatic and environmental conditions in Apulia during the Middle to Upper Palaeolithic transition, when Neanderthals and modern humans coexisted, is presented by Columbu et al., who interpret their findings as indicating that climate did not play a key role in the disappearance of Neanderthals in this area.
• A study on the biological affinities of the Olduvai Hominid 1 is published by Willman et al., who also report evidence from tooth wear indicating that this individual wore three facial piercings.
• A study on an assemblage more than 400 Late Pleistocene human footprints from Engare Sero, and on their implications for the knowledge of the body sizes, locomotor behaviors and composition of the group of humans who generated these tracks, is published by Hatala et al., who interpret these tracks as likely evidence of cooperative and sexually divided foraging behaviors in Late Pleistocene humans.
• A study on the evolution of early symbolic behavior in Homo sapiens, based on data from the engraved ochre and ostrich eggshell fragments from the South African Blombos Cave and Diepkloof Rock Shelter dating up to about 100,000 years ago, is published by Tylén et al..
• Hublin et al. report the discovery and study the age of human remains found in association with Initial Upper Paleolithic artefacts from the Bacho Kiro cave, and argue that this assemblage represents the earliest arrival of Upper Paleolithic Homo sapiens in Europe reported so far; a study on the ¹⁴C chronology of this site is published by Fewlass et al..
• A study aiming to determine the varying reliance of early human colonisers of Wallacea on tropical forest and terrestrial versus marine resources, as indicated by stable carbon and oxygen isotope data from human and faunal tooth enamel from six Late Pleistocene/Holocene archaeological sequences on Timor and Alor Island, is published by Roberts et al..
• Evidence from fecal biomarkers indicating that pre-Clovis coprolites from the Paisley Caves complex are human is presented by Shillito et al..
• A study on the timing of the peopling of the Americas, based on chronometric data from 42 North American and Beringian archaeological sites, is published by Becerra-Valdivia & Higham.
• Evidence of human presence in the Americas during the Last Glacial Maximum is reported from the Chiquihuite Cave by Ardelean et al.'', who interpret their findings as pushing back dates for human dispersal to the region possibly as early as 33,000–31,000 years ago.

  New taxa

Other eutherians

• A study on the anatomy of the petrosal and inner ear of Ocepeia daouiensis is published by Gheerbrant, Schmitt & Billet.
• A study on the dietary habits of Macrauchenia patachonica and Xenorhinotherium bahiense is published by de Oliveira et al..
• Virtual endocast of the stem lagomorph Megalagus turgidus is reconstructed by López-Torres et al..
• A study on the morphology of teeth and likely dietary ecology of the fossil treeshrews Prodendrogale yunnanica and Ptilocercus kylin is published by Selig et al..
• A study on the anatomy of the skull of Microsyops annectens is published by Silcox, Gunnell & Bloch.

Other mammals

• A study on the evolution of morphological diversity of fourth premolars in cimolodontan multituberculates is published by Weaver & Wilson.