Dental Anomaly in Hapalodectes dux (Hapalodectidae, Mesonychia) from the Late Paleocene of Mongolia

The holotype of Hapalodectes dux Lopatin, 2001 from the Upper Paleocene of Mongolia (Tsagan-Khushu locality, Naran Bulak Formation, Zhigden Member) is a lower jaw with complete dentition, showing healed alveoli in place of the right P3. Examination of the holotype using X-ray microtomography revealed a rare dental anomaly previously unknown in fossil mammals, namely the presence of the inverted (positioned upside down and rotated lingual side labially) impacted premolar inside the dentary. The cause of this anomaly may be an aberration of a tooth bud location or an injury.

Insights on the Early Pleistocene Hominin Population of the Guadix-Baza Depression (SE Spain) and a Review on the Ecology of the First Peopling of Europe

The chronology and environmental context of the first hominin dispersal in Europe have been subject to debate and controversy. The oldest settlements in Eurasia (e.g., Dmanisi, ∼1.8 Ma) suggest a scenario in which the Caucasus and southern Asia were occupied ∼0.4 Ma before the first peopling of Europe. Barranco León (BL) and Fuente Nueva 3 (FN3), two Early Pleistocene archeological localities dated to ∼1.4 Ma in Orce (Guadix-Baza Depression, SE Spain), provide the oldest evidence of hominin presence in Western Europe. At these sites, huge assemblages of large mammals with evidence of butchery and marrow processing have been unearthed associated to abundant Oldowan tools and a deciduous tooth of Homo sp. in the case of BL. Here, we: (i) review the Early Pleistocene archeological sites of Europe; (ii) discuss on the subsistence strategies of these hominins, including new estimates of resource abundance for the populations of Atapuerca and Orce; (iii) use cartographic data of the sedimentary deposits for reconstructing the landscape habitable in Guadix-Baza; and (iv) calculate the size of the hominin population using an estimate of population density based on resource abundance. Our results indicate that Guadix-Baza could be home for a small hominin population of 350–280 individuals. This basin is surrounded by the highest mountainous reliefs of the Alpine-Betic orogen and shows a limited number of connecting corridors with the surrounding areas, which could have limited gene flow with other hominin populations. Isolation would eventually lead to bottlenecks, genetic drift and inbreeding depression, conditions documented in the wild dog population of the basin, which probably compromised the viability of the hominin population in the medium to long term. This explains the discontinuous nature of the archeological record in Guadix-Baza, a situation that can also be extrapolated to the scarcity of hominin settlements for these ancient chronologies in Europe.

The early hunting dog from Dmanisi with comments on the social behaviour in Canidae and hominins

The renowned site of Dmanisi in Georgia, southern Caucasus (ca. 1.8 Ma) yielded the earliest direct evidence of hominin presence out of Africa. In this paper, we report on the first record of a large-sized canid from this site, namely dentognathic remains, referable to a young adult individual that displays hypercarnivorous features (e.g., the reduction of the m1 metaconid and entoconid) that allow us to include these specimens in the hypodigm of the late Early Pleistocene species Canis (Xenocyon) lycaonoides. Much fossil evidence suggests that this species was a cooperative pack-hunter that, unlike other large-sized canids, was capable of social care toward kin and non-kin members of its group. This rather derived hypercarnivorous canid, which has an East Asian origin, shows one of its earliest records at Dmanisi in the Caucasus, at the gates of Europe. Interestingly, its dispersal from Asia to Europe and Africa followed a parallel route to that of hominins, but in the opposite direction. Hominins and hunting dogs, both recorded in Dmanisi at the beginning of their dispersal across the Old World, are the only two Early Pleistocene mammal species with proved altruistic behaviour towards their group members, an issue discussed over more than one century in evolutionary biology.

Dentition Anomalies in Nesophontidae (Lipotyphla, Mammalia) from the Pleistocene of Cuba

The study of the remains of Nesophontes micrus Allen, 1917 and N. major Arredondo, 1970 from El Abrón Cave (Republic of Cuba, Pinar del Río Province, Late Pleistocene) allowed to establish for the first time anomalies of the dentition in Nesophontidae. Failures of eruption of teeth (impaction of I₃ in N. micrus, retention or impaction of P₂ in N. major), as well as malformations (aberrant I₃ in N. micrus, P₂ and P₄ in N. major), are the developmental abnormalities. The absence of P₂ and M₂ in combination with reossification of their alveoli in N. major is caused by dental injuries and diseases.

Dental pathology of the wild Iberian wolf (Canis lupus signatus): The study of a 20th century Portuguese museum collection

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Dental pathology of wild Iberian wolf was studied in 61 complete skulls and 4 mandibles from a museum collection.

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Museum collections can provide crucial information about wild elusive species.

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The most frequent observed abnormalities were tooth wear, periodontitis and tooth fractures.

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Dental radiography is of a great importance for the diagnose and classification of the dental and periodontal conditions.

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Dental radiography can be useful for the age estimation of archaeological Canis.

For some wild canids, such as the Iberian wolf, there is a lack of in-depth knowledge about dental pathology. We aimed to evaluate it, in a standardized manner, in specimens from a Portuguese museum collection.

Sixty-five deceased specimens of wild Iberian wolves, 61 complete skulls and 4 mandibles, collected in Portugal between 1977 and 1995, were analyzed. Sample comprised 18 females, 24 males and 23 individuals of undetermined sex. Teeth were evaluated by visual observation and dental radiography for tooth wear, periodontitis, fractures and other dental lesions.

We have found several causes for teeth absence: artefactual, secondary to periodontitis and agenesia. About 30% of the teeth showed signs of wear. Only a small (<13%) fraction of maxillary and mandibular teeth did not show periodontitis. The tooth 308 showed periodontitis in all males (p = 0.017) and the tooth 104 was significantly affected by this condition in females (p = 0.020). A significant relationship was found between females and tooth wear in three teeth. Periodontitis showed a significant association with tooth wear (p < 0.001) and fractures (p = 0.027). Tooth fractures were more frequent in the maxilla than in the mandible. Seven periapical lesions, seven root fusions and three specimens with malocclusion were identified in the collection. Results are discussed integrating information from diet, habitat, genetic and spatial behavior.

Dental radiography is here proposed as an approach for the age estimation in archaeological canids. This research contributes to the knowledge of the dental disease in the largest wolf population in Western Europe, a target subspecies of multiple conservation measures.

Dental and Temporomandibular Joint Pathology of the Grey Wolf (Canis lupus)

Skulls from 392 grey wolves (Canis lupus) were examined macroscopically according to predefined criteria. Two hundred and seven skulls were included in this study, comprised of 124 young adults (59.9%) and 83 adults (40.1%); of these, 65 (31.4%) specimens were from male wolves and 104 (50.3%) were from females, with 38 (18.4%) of unknown sex. Out of 8,694 possible teeth, 8,339 (95.9%) were present for evaluation. Fifty-five teeth (15.5%) were absent congenitally, 30 (8.5%) were lost during life and 270 (76.1%) were lost artefactually post mortem. Skeletal or dental malocclusion was present in 37 specimens (17.9%), with level bite being the most commonly encountered malocclusion. Enamel hypoplasia was present in five skulls (2.4%), affecting eight teeth (0.1%) in total. An abnormal number of roots was found on 23 teeth (0.3%) on 13 skulls (6.3%). Persistent deciduous teeth occurred in two (1.0%) specimens, affecting one (0.01%) tooth each. Fenestration or dehiscence was found associated with 203 teeth (2.4%) in 72 skulls (34.8%). Periodontitis was noted on 115 skulls (55.6%) and 1,000 teeth (11.5%), affecting significantly more adults (n = 63, 75.0%) than young adults (n = 52, 41.9%; P <0.0001). One hundred and sixty-one skulls (77.8%) showed signs of endodontal disease, including attrition or abrasion on 144 skulls (69.6%) and 2,522 teeth (30.2%) and 424 fractured teeth (5.1%) on 103 skulls (49.8%). Both lesions affected significantly more adults than young adults. Overt periapical disease was associated with six teeth (0.1%) distributed across five skulls (2.4%). A carious lesion was present on one tooth (0.01%) of one specimen (0.5%). Lesions consistent with temporomandibular joint (TMJ) osteoarthritis were found in 24 specimens (11.6%), affecting 38 joints (9.2%). Trauma to the skull, such as bite marks, bullet holes or blunt trauma, was noted in 44 skulls (21.2%). The grey wolf and the domestic dog (Canis lupus familiaris) share common dental diseases; however, the proportion and severity may vary. Although the clinical significance of dental and TMJ pathology in the grey wolf remains unknown, based on the impact of these disorders on the domestic dog, the occurrence and severity of these lesions are likely to play an important role in the morbidity and mortality of this wild canid species.

The morphology of the mandibular coronoid process does not indicate that Canis lupus chanco is the progenitor to dogs

The domestication of wolves is currently under debate. Where, when and from which wolf sub-species dogs originated are being investigated both by osteoarchaeologists and geneticists. While DNA research is rapidly becoming more active and popular, morphological methods have been the gold standard in the past. But even today morphological details are routinely employed to discern archaeological wolves from dogs. One such morphological similarity between Canis lupus chanco and dogs was published in 1977 by Olsen and Olsen. This concerns the “turned back” anatomy of the dorsal part of the vertical ramus of the mandible that was claimed to be specific to domestic dogs and Chinese wolves C. lupus chanco, and “absent from other canids”. Based on this characteristic, C. lupus chanco was said to be the progenitor of Asian and American dogs, and this specific morphology has been continuously used as an argument to assign archaeological specimens, including non-Asian and non-American, to the dog clade. We challenged this statement by examining 384 dog skulls of 72 breeds and 60 skulls of four wolf sub-species. Only 20 % of dog mandibles and 80 % of C. lupus chanco showed the specific anatomy. In addition, 12 % of Canis lupus pallipes mandibles showed the “turned back” morphology. It can be concluded that the shape of the coronoid process of the mandible cannot be used as a morphological trait to determine whether a specimen belongs to a dog or as an argument in favour of chanco as the progenitor to dogs.

A standardized framework for examination of oral lesions in wolf skulls (Carnivora: Canidae: Canis lupus)

Oral lesions in wolves (Carnivora: Canidae: Canis lupus) are usually reported in a nonstandardized manner, and often only a few abnormalities are indicated. This approach has likely led to underreporting of oral lesions, thus limiting our ability to interpret wolf health conditions and thus making comparisons across geographical and taxonomic groups difficult. Here, we present a standardized oral exam protocol to examine wolf skulls for their oral lesions. Using this protocol, we analyzed 40 skulls of adult wild Middle East wolves representing 1,680 teeth. Six wolves were Canis lupus arabs, 34 were Canis lupus pallipes. Only 3 skulls showed no oral lesions. We were able to identify a large range of oral lesions and refined subclasses, exceeding the variety of what has been reported on wolf oral lesions so far. No statistical differences were found in the type and number of lesions between the 2 subspecies of wolves. Therefore, the lesions were pooled in subsequent analyses. This standardized protocol should provide a useful framework to assess oral lesions in wolf skulls, facilitating rigorous comparisons across geographic and taxonomic groups.

Craniomandibular trauma and tooth loss in northern dogs and wolves: implications for the archaeological study of dog husbandry and domestication

Archaeological dog remains from many areas clearly show that these animals suffered tooth fractures, tooth loss, trauma, and dental defects during their lives. Relatively little research has explored the meanings of these patterns, particularly for ancient dog remains from small-scale societies of the North. One limiting issue is the lack of comparative data on dental health and experiences of trauma among northern wolves and dogs. This paper examines tooth loss, tooth fracture, enamel hypoplasia, and cranial trauma in a large sample of historic dog and wolf remains from North America and Northern Russia. The data indicate that the dogs more commonly experienced tooth loss and tooth fracture than the wolves, despite reportedly being fed mostly soft foods such as blubber and fish. The higher rates observed in the dogs likely is a result of food stress and self-provisioning through scavenging. The ability to self-provision was likely important for the long-term history of dog use in the north. Dogs also more commonly experienced cranial fractures than wolves, particularly depression fractures on their frontal bones, which were likely the result of blows from humans. Hypoplastic lesions are rare in both wolves and dogs, and probably result from multiple causes, including food stress, disease, and trauma.

What the Inbred Scandinavian Wolf Population Tells Us about the Nature of Conservation

The genetic aspects of population health are critical, but frequently difficult to assess. Of concern has been the genetic constitution of Scandinavian wolves (Canis lupus), which represent an important case in conservation. We examined the incidence of different congenital anomalies for 171 Scandinavian wolves, including the immigrant founder female, born during a 32-year period between 1978 and 2010. The incidence of anomalies rose from 13% to 40% throughout the 32-year study period. Our ability to detect this increase was likely facilitated by having considered multiple kinds of anomaly. Many of the found anomalies are likely associated with inbreeding or some form of genetic deterioration. These observations have implications for understanding the conservation needs of Scandinavian wolves. Moreover, these observations and the history of managing Scandinavian wolves focus attention on a broader question, whether conservation is merely about avoiding extinction of remnant populations, or whether conservation also entails maintaining genetic aspects of population health.

Dental pathology in dolphins (Cetacea: Delphinidae) from the southern coast of Brazil

Pathological processes observed in the stomatognathic systems of mammalian species are a useful source of information about the habits, evolution and general health of such animals. Studies of pathological conditions on teeth are common in humans and other primates, but rare in wild animals in general and marine mammals in particular. For cetaceans, previous studies provided scanty records of dental anomalies in a few species. This is the first broad and systematic inventory of dental pathology in dolphins. Specimens stored at scientific collections from the southern coast of Brazil were visually inspected under a stereoscopic microscope using a dental explorer. Diagnosis of lesions and anomalies followed literature descriptions. Abnormalities such as caries-like lesions, mineralized calculus deposits, dental erosion, enamel anomalies (hypoplasia and exogenous pigmentation), root resorption, germination and other shape anomalies, were diagnosed in the delphinids Sotalia guianensis, Delphinus capensis, Stenella frontalis, Stenella coeruleoalba, Lagenodelphis hosei, Pseudorca crassidens, Orcinus orca, Steno bredanensis and Tursiops truncatus. Endogenous causes may be related to the occurrence of certain conditions, but the aetiology of caries-like lesions and calculus accumulation is still unknown for cetaceans. The diagnosis of alveolar anomalies and other bone lesions in specimens with dental pathology lead us to believe these lesions modify the integrity of the periodontal ligament and bony tissues, adding to the burden of morbidity of affected animals.

Dental and skull anomalies in feral coypu, Myocastor coypus

The study of dental and skull abnormalities of wild animals can provide useful information for comparative studies. Although studies of captive and laboratory rodents have been published, there are few reports on wild populations. We examined anomalous and pathological conditions in the skulls of feral coypus, Myocastor coypus, from Aichi Prefecture, Japan, and identified the types of abnormality. Of the 203 coypu skulls of various ages examined, 19 specimens (9.4%) had abnormalities. A total of 23 anomalies were divisible into three categories: dental diseases, dental injuries and skull injuries. Seven specimens (3.4%) had evidence of periodontal disease in the cheek teeth, and one specimen (0.5%) had caries. Seven specimens (3.4%) had broken upper or lower incisors. Four specimens (2.0%) had injured cranial bones and three (1.4%) had fractures near the zygomatic arch. A single specimen (0.5%) had a deformed rostrum. No statistically significant differences between the genders were found in any category (chi2 test: P < 0.05). The incidence of dental disease appeared to be related to the biological characteristics of this species, i.e., long lifespan, herbivorous diet and molar crown morphology. By contrast, dental and skull injuries appeared to be due to trauma caused when farmers attacked feral coypus.

Anomalias e variações na fórmula dentária em morcegos do gênero Artibeus Leach (Chiroptera, Phyllostomidae)

Descreve-se a ocorrência e analisa-se as causas de anomalias dentárias em Artibeus lituratus (Olfers, 1818) e A. fimbriatus Gray, 1838 (Chiroptera: Phyllostomidae) provenientes de populações do Estado do Rio Grande do Sul, sul do Brasil. São discutidas, com base no material examinado e em ampla revisão da literatura, as variações quanto à presença dos terceiros molares superior e inferior entre diferentes espécies de Artibeus Leach, 1821. Foram analisados 104 crânios de A. lituratus e 44 de A. fimbriatus quanto à fórmula dentária. Em A. lituratus ocorreram dois casos de dentes extranumerários, um incisivo superior e um terceiro molar superior direito, e um de agênese dentária dos terceiros molares inferiores. Em A. fimbriatus constatou-se a ocorrência de um segundo pré-molar superior direito extranumerário. As ocorrências do terceiro molar superior em A. lituratus e do segundo pré-molar superior em A. fimbriatus são casos de atavismos. Em Artibeus (Artibeus) ocorrem variações quanto à presença do terceiro molar superior, de maior ou menor intensidade, em praticamente todas as espécies. Estas variações ocorrem tanto a nível intrapopulacional quanto geográfico. Já o terceiro molar inferior está ausente em baixa freqüência em várias populações de diferentes espécies. Os terceiros molares superiores e inferiores estão em processo de desaparecimento na linhagem dos Artibeus (Artibeus). O fato destes dentes já não ocorrerem em algumas espécies, terem ocorrência variável em outras e serem sempre estruturas reduzidas e simplificadas, sem função na mastigação, são indicativos deste processo evolutivo. A variação intensa observada quanto à ocorrência do terceiro molar superior inviabiliza o seu uso como caráter útil na identificação de espécies.