First record of Cynomops planirostris (Peters, 1865) (Chiroptera, Molossidae) from Maranhão state, Brazil, based on morphological and molecular data

Based on morphological and molecular data, we present the first record of Cynomops planirostris for the State of Maranhão. The specimen was collected in the Inhamum Municipal Environmental Protection Area in Maranhão, Brazil and characterized morphologically as an adult male with scrotal testicles, dorsal pelage reddish chestnut, with ventral pelage slightly lighter in color, forearm length 34.70-34.80mm dental formula i:1/1, c:1/1, pm:1/2, m:3/3 = 26. The sequence of the Cytochrome Oxidase I subunit (COI) molecular marker confirmed the morphological diagnosis of the specimen as C. planirostris with significant similarities. The combined analysis of both morphological and molecular confirmed the occurrence of C. planirostris in the Brazilian state of Maranhão, in the Cerrado biome and records extends the known geographic distribution of the species by 411.30 km.

Unexpected inhibitory cascade in the molariforms of sloths (Folivora, Xenarthra): a case study in xenarthrans honouring Gerhard Storch’s open-mindedness

The inhibitory cascade (IC) represents a developmental model that explains the evolution of molar relative sizes, originally described in rodents but later validated in several mammalian groups. The IC comprises signalling molecules produced by the first molar buds that inhibit the development of subsequent molars and molecules from surrounding tissues that have opposite effects. Sloths, as xenarthrans, present many peculiarities in their dentition, like tooth and enamel loss, homodonty, and changes in the typically mammalian dental formula. Here, we test the existence of an IC and explore the evolution of the lower dentition in sloths. We studied the variability of molariform proportions in 20 specimens of the Late Pleistocene ground sloth Lestodon armatus. We also analysed molariforms proportions in 53 sloth genera to explore evolutionary trends. Our results show that the lower dentition of most sloths complies with the IC model, despite the difficulties of assessing dental homologies with other mammals. Furthermore, we tested the existence of different patterns among families, obtaining support for models taking mylodontids and orophodontids separately from the rest of sloths. Also, members of Mylodontidae show a unique IC pattern, with a slope considerably higher than 2 and an mf1 ≤ mf2 << mf3 configuration. This pattern could be related to the morphological adaptations to grazing showed by mylodontids during most of their evolutionary history.

A new primate from the late Eocene of Vietnam illuminates unexpected strepsirrhine diversity and evolution in Southeast Asia

Sivaladapidae is a poorly known Asian strepsirrhine family originally discovered in Miocene sediments of the Indian subcontinent. Subsequent research has considerably increased the diversity, temporal range, and geographical distribution of this group, now documented from China, Thailand, Myanmar, Pakistan, and India and whose earliest representatives date back to the Middle Eocene. We present here a new taxon of sivaladapid from the Na Duong coal mine in the Latest Middle Eocene-Late Eocene of Vietnam. It represents the first Eocene primate from Vietnam and the first medium-sized mammal recovered from this locality, thus documenting a completely new part of the Na Duong paleobiodiversity. This taxon is the largest sivaladapid ever found with an estimated body weight of 5.3 kg and it represents a new subfamily of sivaladapids in exhibiting a very peculiar combination of dental features yet unknown in the fossil record of the family (e.g., retention of four premolars, high-crowned molars with accentuated bunodonty and extreme crest reduction). Besides documenting a complete new part of sivaladapid evolution, its primitive dental formula and derived features shared with the Early Eocene Asiadapidae reinforce the hypothesis of a basal branching of sivaladapids among strepsirrhines.

Anatomical and Radiographic Study on the Skull and Mandible of the African Lion (Panthera leo)

Objective The taxonomic affiliations can be detected via the skull morphology. The objective of this study was to give a detailed gross anatomical and radiographic description of the bones and foramina of the skull and mandible of the lion. This information could be used in the identification of the skull and mandible of the lion, which is of great importance in taxonomic affiliation and to help the zoo veterinarians to detect, diagnose, and treat head conditions. Materials and Methods The current work was conducted on two skulls and mandibles of lions. The skulls and mandible were prepared using standard boiling and maceration technique. The gross and radiographic photos of the bones and foramina of the skull and mandible were taken using a Kodak digital camera and Siemens mobile full wave X-ray machine (Siemens Medical Solutions, Erlangen, Germany). Results The skull of the lion comprised of facial and cranial parts. The nasal openings were large, and the bony orbit was incomplete. The supraorbital foramen was absent. The zygomatic arch was large. The frontal region had a deep longitudinal depression dorsally. The mandible was a paired bone with movable articulation, and it had strongly excavated masseteric fossa with a well-developed crest. The dental formula was 30 teeth consisting of small incisors, long canines and carnassial premolars. Conclusion The current study showed that the osteology and foramina of the skull and mandible of the lion were similar to those of other mammals. The information is important for taxonomic affiliation, and wildlife forensic as well as to help the zoo veterinarians to manage clinical head diseases in this species.

Description of a new species of Leporinus (Characiformes: Anostomidae) from the Rio Tapajós basin, Brazil

A new species of Leporinus is described from the rio Teles Pires, rio Tapajós basin, Amazon basin, Brazil. The new species is diagnosed based on dental formula 3/4, a dark midlateral stripe on body and a series of transversal dark bars on the dorsum. The new species is similar to a handful of congeners based on the color pattern, including L. britski, L. microphysus, L. parvulus, and L. vanzoi, all of which also occur at the rio Tapajós basin. The new species is distinguished from the aforementioned congeners based on number of premaxillary teeth, number of scales in lateral line and/or around caudal peduncle. The new species is apparently endemic to the rio Teles Pires near the Sete Quedas rapids and upstream.

Skull Bone Anatomy of the Young Common Hippopotamus (Hippopotamus Amphibius)

Hippopotamidae family is nowadays represented by two species within two different genera: pygmy hippopotamus (Choeropsis liberiensis) and common hippopotamus (Hippopotamus amphibius). The common hippopotamus has a very unique anatomy, and the shape of the body, especially the head is adapted for a semi-aquatic life style. The morphological examination and description of the gross anatomical features of the hippopotamus skull is described in this paper. The shape of the skull is adapted for the amphibian way of life. Their eyes, ears and nostrils are placed high on the roof of the skull which allows these organs to remain above the surface of the water while the animal is being submerged underwater. The skull is massive, but the brain case (neurocranium) is extremely small compared with the splanchnocranium and complete head. The dental formula of the common hippopotamus is: incisors (I) 2/2, canines (C) 1/1, premolars (P) 3-4/3-4 and molars (M) 3/3. Incisors and canine teeth are formed in the shape of tusks and are used for threat or “demonstration of power” among animals when vigorously fi ghting. Incisor teeth grow continuously and are twice bigger in males than in females.

Supernumerary Tooth: A Common Odontostomatologic Anomaly Of Number Of Teeth

Supernumerary tooth (ST) is a developmental disturbance of number of teeth characterized by teeth present in excess of normal dental formula of deciduous or permanent dentition.1,2,3,4 It may occur in either dental arch, maxillary or mandibular.5 Literature has shown marked predilection in maxilla over mandible.6,7 The first documented report of supernumerary teeth has been revealed in human fossils that are approximately 11,000 years old.8

Number dental anomalies: Supernumerary in triplets. Literature review and case report

Supernumerary teeth are considered as one of the dental anomalies where there is a development and/or training of a larger number of teeth. These may be isolated or associated with a syndrome, which can cause complications in the eruption, occlusion and a esthetics. Although the etiology of supernumerary is unknown, some authors make mention of theories as the dichotomy of tooth germ, hyperactivity of the dental lamina and genetic alterations, with matching patterns partnerships with autosomal dominant or autosomal recessive inheritance linked to X chromosome. Given the genetic importance in the development of supernumerary it is conceivable that in the case of sharing the same information, if a disturbance occurs in the dental formula, this should be repeated in his brothers. According to this view with a geneticist perspective this paper presents the situation of three triplets tricigoticos presenting alteration in a dental formula in terms interchangeably affected dentition (decidua and/or permanent) position on the bow (right or left) and impacted tooth. Key words: Dental anomalies, supernumerary, triplets.