[Most Recent Entries] [Calendar View]
Monday, September 28th, 2020
| Time | Event | ||||||
| 3:54a | [PaleoMammalogy • 2020] Rhaphicetus valenciae • A New Longirostrine Sperm Whale (Cetacea, Physeteroidea) from the lower Miocene of the Pisco Basin (southern coast of Peru)
Abstract The modern sperm whales Kogia and Physeter (superfamily Physeteroidea) represent highly disparate, relict members of a group of odontocetes that peaked in diversity during the middle to late Miocene. Based on a highly informative specimen (including the cranium with ear bones, mandibles, teeth and some postcranial elements) from the lower Miocene (early Burdigalian, 19–18 Ma) of the Chilcatay Formation (Pisco Basin, Peru), we describe here a new genus and species of physeteroid, Rhaphicetus valenciae gen. et sp. nov. The latter is one of the geologically oldest physeteroids. This medium-sized species (estimated body length between 4.7 and 5.7 m) differs from all other physeteroids by the following, probably autapomorphic, features: a narrow, cylindrical rostrum comprising nearly 75% of the condylobasal length; the two main dorsal infraorbital foramina located posterior to the antorbital notch; an upper tooth count of at least 36 teeth per quadrant; and anterior-most upper alveoli filled by thick bony pads. Our phylogenetic analysis recovers R. valenciae as one of the earliest branching stem physeteroids. The highly unusual filling of the anterior upper alveoli by bony pads is interpreted as part of a mechanism leading to the loss of apical and subapical upper teeth. By comparison with other odontocetes displaying some degree of anterior reduction of the dentition, this condition may have corresponded to the rostrum being anteriorly longer than the mandible. The elongated rostrum with a circular cross-section, the long temporal fossa, and the high number of slender, pointed upper and lower teeth all suggest that R. valenciae used its dentition to grasp relatively small prey, possibly via rapid movements of the head. On the one hand, this new Peruvian record increases our knowledge of the morphological disparity of sperm whales during the Miocene. On the other hand, it may provide clues to the ancestral morphotype for all physeteroids. Keywords: Burdigalian, dental reduction, functional morphology, palaeobiology, phylogeny, stem Physeteroidea
Systematic palaeontology Order Cetacea Brisson, 1762 Pelagiceti Uhen, 2008 Neoceti Fordyce & Muizon, 2001 Suborder Odontoceti Flower, 1867b Superfamily Physeteroidea Gray, 1821 Genus Rhaphicetus gen. nov. Type species. Rhaphicetus valenciae sp. nov. Derivation of name. From the ancient Greek rhaphis, needle, and from the Latin cetus, whale: the whale with a needle-shaped rostrum. Rhaphicetus valenciae sp. nov. Derivation of name. valenciae, honouring Dr Niels Valencia Marciano Chacón, a biologist at the Universidad Nacional Mayor de San Marcos studying plant ecology and the director of the MUSM, for his constant support for the palaeontological activities at that institution, including many fruitful palaeontological expeditions in the Pisco Basin.  Olivier Lambert, Christian de Muizon, Mario Urbina and Giovanni Bianucci. 2020. A New Longirostrine Sperm Whale (Cetacea, Physeteroidea) from the lower Miocene of the Pisco Basin (southern coast of Peru). Journal of Systematic Palaeontology. 18(20); 1707-1742. DOI: 10.1080/14772019.2020.1805520  18 Million Year Old Sperm Whale With 'Needle-Shaped' Snout | ||||||
| 4:04a | [Entomology • 2020] Contribution to the Knowledge of Rhaphidophorinae (Orthoptera: Ensifera: Rhaphidophoridae) from Thailand: Three Genera Neorhaphidophora, Eurhaphidophora & Minirhaphidophora
Abstract A new subgenus, three new species and a new subspecies of the rhaphidophorines are described from Thailand: Minirhaphidophora (Condylophora) ophioglossa subgen. et sp. nov., Neorhaphidophora siamensis sp. nov., Eurhaphidophora pawangkhananti sp. nov., and Eurhaphidophora tarasovi doitungensis ssp. nov. Keys to all known species with regard to the genera Neorhaphidophora and Minirhaphidophora, as well as a key to the Thai species of the genus Eurhaphidophora, are provided. Keywords: Orthoptera, Rhaphidophoridae, taxonomy, Thailand, new taxa
Genus Neorhaphidophora Gorochov, 1999 Neorhaphidophora siamensis Dawwrueng, Gorochov et Suwannapoom sp. nov. Etymology The new species is named after “Siam” (the old name of Thailand). Genus Eurhaphidophora Gorochov, 1999 Thai species of Eurhaphidophora Eurhaphidophora pawangkhananti sp. nov. Eurhaphidophora bispina Gorochov, 2010 Eurhaphidophora tarasovi doitungensis ssp. nov. Eurhaphidophora tarasovi doitungensis Dawwrueng, Gorochov et Suwannapoom ssp. nov. Etymology The new species is named after the location from where it was collected, Doi Tung Development Project Area. Eurhaphidophora pawangkhananti Dawwrueng, Gorochov et Suwannapoom sp. nov. Etymology The new species is named after Mr. Parinya Pawangkhanant, a young Thai herpetologist who assisted in collecting specimens during fieldwork.
Genus Minirhaphidophora Gorochov, 2002 Subgenus Condylophora Dawwrueng, Gorochov et Suwannapoom subgen. nov. Type species Minirhaphidophora (Condylophora) ophioglossa sp. nov. Etymology The new subgeneric name originated from the Latinized Greek word “condylus” (tubercle) and the generic name “Rhaphidophora”. This is because the male of this subgenus has a pair of characteristic tubercles on its tenth abdominal tergite. Minirhaphidophora (Condylophora) ophioglossa Dawwrueng, Gorochov et Suwannapoom sp. nov. Etymology The name of the new species originates from the Latinized Greek words “ophis” (snake) and “glossa” (tongue). This is because the apical part of the male epiproct in this species is more or less similar to a snake’s tongue in shape. Pattarawich Dawwrueng, Andrei V. Gorochov, Alongklod Tanomtong and Chatmongkon Suwannapoom. 2020. Contribution to the Knowledge of Rhaphidophorinae (Orthoptera: Ensifera: Rhaphidophoridae) from Thailand: Three Genera Neorhaphidophora, Eurhaphidophora and Minirhaphidophora. Zootaxa. 4853(2); 235–253. DOI: 10.11646/zootaxa.4853.2.5 |
| << Previous Day |
2020/09/28 [Calendar] |
Next Day >> |