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Sunday, January 10th, 2016
| Time | Event | ||||
| 8:17a | [PaleoOrnithology • 2015] Cratoavis cearensis • A New Genus and Species of Enantiornithine Bird from the Early Cretaceous of Brazil  ABSTRACT The fossil record of birds in Gondwana is almost restricted to the Late Cretaceous. Herein we describe a new fossil from the Araripe Basin, Cratoavis cearensis nov. gen et sp., composed of an articulated skeleton with feathers attached to the wings and surrounding the body. The present discovery Considerably extends the record time of the enantiornithes birds at South America to the Early Cretaceous. For the first team, an almost complete and articulated skeleton of an Early Cretaceous bird from South America is documented. Keywords: Cratoavis cearensis nov. gen et sp .; Araripe Basin; fossil bird SYSTEMATIC PALEONTOLOGY Aves Linnaeus 1758 Ornithothoraces Chiappe 1996 Enantiornithes Walker 1981 Euenantiornithes Chiappe & Walker 2001 Cratoavis cearensis nov. gen. et sp. (Figs. 3 and 4) Etymology: Cratoavis nov. gen., the generic name derives from the combination of the Crato Member lithostratigraphic unit, where the specimen was found, and the zoological group Aves. The specific epithet cearensis refers to the Ceará State, where the fossil was collected. Locality and horizon: Pedra Branca Mine, Nova Olinda County, Ceará State, Brazil (7° 6´51.9´´ S and 39° 41´46.9´´ W). Araripe Basin, Santana Formation, Crato Member (Early Cretaceous, Aptian). This formation has yielded abundant and exceptionally preserved fossils of a large variety of plants and animals, representing one of the best well-known terrestrial ecosystems for the Early Cretaceous. Isolated feathers probably belonging to birds have been described from these beds, as well as succinct reports on avian skeletons associated with poorly preserved feathers. CONCLUSIONS Cratoavis cearensis nov. gen. et sp. constitutes the first named bird from the Mesozoic of Brazil and the Early Cretaceous of South America. It constitutes an important addition to the meager record of South American Cretaceous birds, and constitutes one of the more complete Mesozoic bird specimen from Gondwana. It also expands the list in which skeletal elements have been found in association with feathers, including long tail rectrices. Ismar Carvalho, Fernando E. Novas, Federico L. Agnolin, Marcelo P. Isasi, Francisco I. Freitas and Jose A. Andrade. 2015. A New Genus and Species of Enantiornithine Bird from the Early Cretaceous of Brazil. Brazilian Journal of Geology. 45(2): 161-171. DOI: 10.1590/23174889201500020001 RESUMO: No Gondwana, o registro fóssil de aves está praticamente restrito ao Cretáceo Superior. Neste estudo é descrito um novo fóssil da Bacia do Araripe, Cratoavis cearensis nov. gen. et sp., composto por um esqueleto articulado com penas conectadas às asas e circundando o corpo. A presente descoberta amplia consideravelmente o intervalo temporal de registro das aves Enantiornithes na América do Sul ao Cretáceo Inferior. Pela primeira vez, um esqueleto articulado e quase completo de uma ave do Cretáceo Inferior da América do Sul é documentado. PALAVRAS-CHAVE: Cratoavis cearensis nov. gen. et sp.; Bacia do Araripe; Ave fóssil.     Ismar de Souza Carvalho, Fernando E. Novas, Federico L. Agnolín, Marcelo P. Isasi, Francisco I. Freitas and José A. Andrade. 2015. A Mesozoic Bird from Gondwana preserving Feathers. Nature Communications. DOI: 10.1038/ncomms8141 Photos: Dinosaur-Era Bird Sported Ribbonlike Feathers | ||||
| 8:40a | [PaleoOrnithology • 2015] Feitianius paradisi • A New Early Cretaceous Enantiornithine (Aves, Ornithothoraces) from northwestern China with Elaborate Tail Ornamentation
ABSTRACT We provide a detailed description of a well-preserved enantiornithine specimen (GSGM-05-CM-004) from the Lower Cretaceous (Aptian) Xiagou Formation of northwestern Gansu Province, China, for which we erect the new taxon Feitianius paradisi, gen. et sp. nov. This specimen has a distinctive pelvic morphology and can be further distinguished from all other Mesozoic birds by a unique caudal plumage formed by multiple rectricial morphotypes. This newly documented tail morphology reveals a previously unrecognized level of complexity in the plumage of basal birds. This complex tail-feather morphology has a parallel in extant sexually dimorphic birds in which the males have the most altered tails; thus, we identify this specimen as male. Ornamental tail morphologies, such as the novel tail plumage described here, dominate Enantiornithes. This reinforces hypotheses that sexual selection was a major driving force in the evolution of basal bird plumage. SYSTEMATIC PALEONTOLOGY AVES Linnaeus, 1758 ORNITHOTHORACES Chiappe, 1995aENANTIORNITHES Walker, 1981 FEITIANIUS PARADISI, gen. et sp. nov. Holotype — GSGM-05-CM-004, an incomplete but articulated specimen preserving the caudal half of the skeleton (mostly inleft lateral view) on a single slab, including carbonized vestigesof the caudal body coverts, rectrices, and keratinous pedalungual sheaths. Etymology — Feitianius paradisi, meaning Paradise’s feitian (飞天), referring to the hundreds of paintings of feitian, or ‘flying apsara,’ in the Mogao caves that are not far from the type locality. Like the new species, the feitian were beautiful flying creatures. ‘Paradisi’ (Latin, genitive ‘from paradise’) refers to the similarity in tail morphology between the new fossil and the highly sexually dimorphic plumages of extant birds of paradise. For fun, we decided to masculinize the genus name because the holotype specimen appears to be a male. Locality and Horizon — Lower Cretaceous (lower–middle Aptian) (124–120 Ma; (Suarez et al., 2013) Xiagou Formation,near Changma Village, Yumen City, Gansu Province, northwestern China. Taxonomic Remarks — The specimen can be referred to Enantiornithes based on its possession of the following characters: excavated thoracic vertebrae with centrally located parapophyses; distinctive, large pygostyle with craniodorsal fork, ventrolateral processes, and distal constriction; ischium with strap-like proximodorsal process; and reduced metatarsal IV. Specimen GSGM-05-CM-004 can be differentiated from Qiliania graffini Ji et al., 2011, another enantiornithine from the same formation, by several features. First, Feitianius paradisi bears a medial plantar crest on metatarsal II (absent in Q. graffini).Although the proportions of the pubis and ischium are similar between the two taxa, the dorsal (caudal) margin of the pubis and ventral (cranial) margin of the ischium are concave in F. paradisi, whereas both of these surfaces are relatively straight in Q. graffini. Furthermore, the proportions of the pedal digits are quite different: the combined length of digit III compared with that of metatarsal III is 1.05 in the new species compared with0.92 in Q. graffini; the same ratio for digit II is 0.77 in F. paradisi and 0.70 in Q. graffini. In addition, in F. paradisi, the hallucal claw is comparatively more recurved and the penultimate phalanx of digit III is subequal in length to the proximal phalanx (the proximal phalanx is longest in Q. graffini). The pubis of the indeterminate Xiagou Formation enantiornithine GSGM-04-CM-007 is rod-like, and its distal end is curved 90 to the proximal shaft (Lamanna et al., 2006), whereas in Feitianius the pubis is dorsoventrally compressed and ends in a pubic boot. Unfortunately, there are no overlapping skeletal elements to comparewith Dunhuangia lii Wang et al., 2015, a newly described enantiornithine from Changma (Wang et al., 2015). Compared with other enantiornithines, the pygostyle is proportionally shorterthan in species of the Longipterygidae, the tarsometatarsus is considerably more gracile than in all species within the Bohaiornithidae or Avisauridae, and the metatarsal and digit I are shorter than in species of the Pengornithidae. Feitianius paradisiis most similar to Jehol ‘cathayornithiforms’ such as species of Cathayornis, Eoenantiornis, Protopteryx, and Sinornisbut differs from these taxa in the detailed anatomy of the pelvic girdle. Jingmai K. O’Connor, Da-Qing Li, Matthew C. Lamanna, Min Wang, Jerald D. Harris, Jessie Atterholt and Hai-Lu You. 2015. A New Early Cretaceous Enantiornithine (Aves, Ornithothoraces) from northwestern China with Elaborate Tail Ornamentation. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2015.1054035  Feitianius, new enantiornithine from Early Cretaceous of China | ||||
| 2:05p | [Paleontology • 2015] A Vanished History of Skeletonization in Cambrian Comb Jellies (Ctenophora)
Abstract Ctenophores are traditionally regarded as “lower” metazoans, sharing with cnidarians a diploblastic grade of organization. Unlike cnidarians, where skeletonization (biomineralization and sclerotization) evolved repeatedly among ecologically important taxa (for example, scleractinians and octocorals), living ctenophores are characteristically soft-bodied animals. We report six sclerotized and armored ctenophores from the early Cambrian period. They have diagnostic ctenophore features (for example, an octamerous symmetry, oral-aboral axis, aboral sense organ, and octaradially arranged ctene rows). Unlike most modern counterparts, however, they lack tentacles, have a sclerotized framework, and have eight pairs of ctene rows. They are resolved as a monophyletic group (Scleroctenophora new class) within the ctenophores. This clade reveals a cryptic history and sheds new light on the early evolution of this basal animal phylum. Skeletonization also occurs in some other Cambrian animal groups whose extant members are exclusively soft-bodied, suggesting the ecological importance of skeletonization in the Cambrian explosion. Keywords: Cambrian, Chengjiang biota, Ctenophora, skeleton
Qiang Ou, Shuhai Xiao, Jian Han, Ge Sun, Fang Zhang, Zhifei Zhang and Degan Shu. 2015. A Vanished History of Skeletonization in Cambrian Comb Jellies. Science Advances. 1(6); e1500092. DOI: 10.1126/sciadv.1500092 | ||||
| 2:57p | [PaleoMammalogy • 2016] Ounalashkastylus tomidai • A New Desmostylian Mammal from Unalaska (USA) and the robust Sanjussen jaw from Hokkaido (Japan), with comments on feeding in derived desmostylids
Abstract Derived members of the enigmatic mammalian order Desmostylia have molars comprising appressed columns whose morphology does not render their function in feeding simple to discern. Here we describe a new genus and species, Ounalashkastylus tomidai, more derived than Cornwallius but less derived than Desmostylus and Vanderhoofius, which develop a hypertrophied medial eminence on the dentary ontogenetically. Tooth morphology, vaulted palate and the medial eminence, which can rise to the level of the occlusal surface of M2, suggest that derived desmostylids clenched their teeth strongly while employing suction during feeding, most likely on marine and coastal plants. Keywords: marine mammal, phylogeny, paleoecology, North Pacific  Systematic paleontology Mammalia Desmostylia Desmostylidae Ounalashkastylus tomidai new genus and species Type specimen. MOTA 2004.009.03 nearly complete left dentary with C1,P4root, M1, and M2. Etymology. Genus after the Aleut word Ounalashka, meaning ‘near the peninsula’, and from which Unalaska is derived; plus –stylus, Latin ‘column’, in reference to desmostylians. Specific name in honour of Dr. Yukimitsu Tomida, distinguished vertebrate paleontologist. Diagnosis. Desmostylid differing from Ashoroa and more basal Desmostylia in having cylindrical, stylodont cuspsthat wear into rings of enamel surrounding exposed dentine;more derived than Cornwallius in having six or more cusps on lower molars; cheek teeth lower crowned (more primitive) than Desmostylus when compared at a similar minor stage of wear on homologous cusps and as shown by the curvature of the walls of the cylindrical cusps from the base of the crown toward the occlusal surface; less derived than Desmostylus and Vanderhoofius but similar to Cornwalliusin that erupted M3 does not lie in a trough developed by a medial eminence; M3 elongate compared to Desmostylus. Type locality and age. Arriaga Quarry (now the site of a school), Unalaska, Unalaska Island, Alaska. Dutch Harbor Member, Unalaska Formation. The geological setting and age were discussed by Jacobs et al. (2007) who concluded that geological and biochronological limits (excluding the evolutionary stage of Ounalashkastylus) lay between 24.1 and 13 Ma, but that the locality most likely falls near the Oligocene-Miocene boundary (23.03 Ma), or slightly younger.  Kentaro Chiba, Anthony R. Fiorillo, Louis L. Jacobs, Yuri Kimura, Yoshitsugu Kobayashi, Naoki Kohno, Yosuke Nishida, Michael J. Polcyn and Kohei Tanaka. 2016. A New Desmostylian Mammal from Unalaska (USA) and the robust Sanjussen jaw from Hokkaido (Japan), with comments on feeding in derived desmostylids. Historical Biology. 28(1-2); 289–303. DOI: 10.1080/08912963.2015.1046718 New fossils intensify mystery of short-lived, toothy mammals unique to ancient North Pacific Oddball creature, Desmostylia, from waters where “Deadliest Catch” TV show is filmed, ate like a vacuum cleaner and is new genus and species of the only order of marine mammals ever to go extinct — surviving a mere 23 million years Extinct Hippolike Creature Was Prehistoric Vacuum Cleaner https://shar.es/16ADEY via @LiveScience The Archaeology News Network: New fossils of short-lived, toothy mammal found in ancient North Pacific http://archaeologynewsnetwork.blogspot.c |
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