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Tuesday, August 20th, 2024
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| 12:31p | [PaleoOrnithology • 2024] Agapornis longipes • A New Species of Lovebird (Aves: Psittaculidae: Agapornis) from the Plio-Pleistocene of the Cradle of Humankind (Gauteng, South Africa)
Abstract A new parrot species of the genus Agapornis (Aves, Psittaculidae), namely Agapornis longipes nov. sp., is described from the Plio-Pleistocene of Kromdraai, Cooper’s Cave, and Swartkrans in the Cradle of Humankind, South Africa. The new species is represented by all major wing bones (humerus, ulna, and carpometacarpus) and by the tarsometatarsus, together with a fragmentary mandible and coracoid. The size of the bones indicates a small species of Agapornis with an elongated tarsometatarsus, proportionately the longest of all known species of Agapornis. This lengthening of the legs might be related to feeding adaptation of the extinct species, as the longer legs may have favored this ground feeder in the high and dense grassland characteristic of the Cradle of Humankind during the Plio-Pleistocene transition and the Early Pleistocene. Keywords: Birds, Parrot, Osteology, Paleoecology, Cooper’s Cave, Kromdraai, Swartkrans Systematic paleontology Aves Linnaeus, 1758 Psittaciformes Wagler, 1830 Psittaculidae Vigors, 1825 Agapornithinae Salvin, 1882 Genus Agapornis Selby, 1836
Agapornis longipes nov. sp. Derivation of the name: The new species shows the longest tarsometatarsus of all extant and extinct species of Agapornis in proportion to the humerus, as shown by the ratio of humerus to tarsometatarsus lengths. Holotype: KWPoc 70e, complete right tarsometatarsus.
Marco Pavia, José Braga, Massimo Delfino, Lazarus Kgasi, Albrecht Manegold, Christine Steininger, Bernhard Zipfel and Aurore Val. 2024. A New Species of Lovebird (Aves, Psittaculidae, Agapornis) from the Plio-Pleistocene of the Cradle of Humankind (Gauteng, South Africa). Geobios. In Press. DOI: doi.org/10.1016/j.geobios.2024.05.006 | ||||||
| 4:27p | [Paleontology • 2024] Alpkarakush kyrgyzicus • A new theropod dinosaur (Theropoda: Metriacanthosauridae) from the Callovian Balabansai Formation of Kyrgyzstan
Abstract Recent fieldwork in the late Middle Jurassic Balabansai Formation of Kyrgyzstan has yielded a partial skeleton of a large theropod dinosaur. The material includes a few bones of the skull (postorbital, quadratojugal), dorsal and sacral vertebrae, fragments of the pectoral girdle and forelimbs, and an almost complete pelvic girdle and hindlimbs, and is here made the type of a new theropod taxon, Alpkarakush kyrgyzicus gen. et sp. nov. Alpkarakush can be diagnosed by an extremely developed orbital brow on the postorbital, a pneumatic opening leading into cavities in the neural arch from the centroprezygodiapophyseal fossa in the posterior dorsal vertebrae, an almost enclosed ventral sulcus in manual phalanx II-1, a narrow and deep intercondylar groove on the anterior side of the distal femur, and an epicondylar crest on the distal femur that is offset from the distal end. A second, fragmentary, and smaller specimen from the same site represents the same taxon. Based on long bone histology, the type of Alpkarakush represents a late subadult individual, whereas the smaller specimen is a juvenile, possibly indicating gregarious behaviour. Phylogenetic analysis places Alpkarakush in the Metriacanthosauridae, underlining the diversity and wide distribution of this clade in the Jurassic of Asia. Central Asia, Middle Jurassic, Tetanurae, Metriacanthosauridae, bone histology
SYSTEMATIC PALAEONTOLOGY Dinosauria Owen, 1842, Saurischia Seeley, 1887, Theropoda Marsh, 1881, Tetanurae Gauthier, 1986, Metriacanthosauridae Paul, 1988 Alpkarakush gen. nov. Etymology: Named after Alpkarakush, a mythological large bird [Алпкаракуш] that often comes to the help of heroes in critical moments in the ‘Manas’ epos, one of the central mythological elements in Kyrgyz culture (Seiilbek et al. 2018). Alpkarakush kyrgyzicus sp. nov. Etymology: The species epithet refers to the Kyrgyz Republic, the provenance of the type specimen. Diagnosis: Alpkarakush kyrgyzicus can be diagnosed by the following combination of characters (autapomorphies are indicated by *): extremely developed supraorbital brow on the postorbital, overhanging the orbit; posterior dorsal vertebrae with a channel leading from the centroprezygodiapophyseal fossa posteromedially into pneumatic chambers in the neural arch*; sacral vertebrae with fused neural spines that are approximately as high as the combined height of the vertebral centrum plus neural arch; manual phalanx II-1 with a ventral sulcus proximally that is almost completely enclosed by medial and lateral ventral flanges*; dorsal margin of the ilium slopes steeply posteroventrally*; brevis fossa on ilium reduced to a small medial shelf; shaft of pubis strongly bowed anteriorly; well-developed longitudinal depression on the posterolateral side of the pubic shaft adjacent to the pubic boot (based on paratype); unusually high pubis/tibia ratio (1.22 or higher); articulated ischia with pronounced ischial boots that are convex distally and fused anteriorly, but separated posteriorly; ischium with small obturator flange that is offset from the pubic peduncle; pubic peduncle of ischium very long; iliac articulation in proximal ischium cup-shaped; narrow and deep intercondylar groove on the anterior side of distal femur*; robust and well-developed medial epicondylar crest on distal femur, considerably offset proximally from distal end*; tibia with robust, bulbous fibular flange; astragalus and calcaneum fused. Type locality and horizon: Locality FTU-1, just west of the town of Tashkumyr, Jalal-Abad Oblast, Kyrgyzstan (Figs 1, 2). The specimens were found in the higher part of the Balabansai Formation, Callovian.  Oliver W. M. Rauhut, Aizek A. Bakirov, Oliver Wings, Alexandra E. Fernandes and Tom R. Hübner. 2024. A new theropod dinosaur from the Callovian Balabansai Formation of Kyrgyzstan. Zoological Journal of the Linnean Society. 201(4); zlae090. DOI: doi.org/10.1093/zoolinnean/zlae090  |
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