نتایج جستجو برای: late cretaceous period falcon

تعداد نتایج: 672578  

2017
Min Wang Jingmai K O'Connor Yanhong Pan Zhonghe Zhou

Enantiornithes are the most successful clade of Mesozoic birds. Here, we describe a new enantiornithine bird, Cruralispennia multidonta gen. et sp. nov., from the Protopteryx-horizon of the Early Cretaceous Huajiying Formation of China. Despite being among the oldest known enantiornithines, Cruralispennia displays derived morphologies that are unexpected at such an early stage in the evolution ...

2006
Yasuhiro Iba Shin-ichi Sano

In this paper, we describe an Aptian (Early Cretaceous) larger foraminiferal species Orbitolina (Mesorbitolina) parva from the limestone olistoliths in the lower part of the Yezo Group in the Yubari-Ashibetsu area, central Hokkaido and from limestone pebbles in the lowermost part of the Yezo Group in the Nakagawa area, northern Hokkaido. This is the first report of this species from the circum-...

2014
Christian Linnert Stuart A. Robinson Jackie A. Lees Paul R. Bown Irene Pérez-Rodríguez Maria Rose Petrizzo Francesca Falzoni Kate Littler José Antonio Arz Ernest E. Russell

The Late Cretaceous 'greenhouse' world witnessed a transition from one of the warmest climates of the past 140 million years to cooler conditions, yet still without significant continental ice. Low-latitude sea surface temperature (SST) records are a vital piece of evidence required to unravel the cause of Late Cretaceous cooling, but high-quality data remain illusive. Here, using an organic ge...

2015
Joseph A. Frederickson Scott N. Schaefer Janessa A. Doucette-Frederickson Laurent Viriot

Three large lamniform shark vertebrae are described from the Lower Cretaceous of Texas. We interpret these fossils as belonging to a single individual with a calculated total body length of 6.3 m. This large individual compares favorably to another shark specimen from the roughly contemporaneous Kiowa Shale of Kansas. Neither specimen was recovered with associated teeth, making confident identi...

Journal: :Anais da Academia Brasileira de Ciencias 2011
Etiene F Pires Margot Guerra-Sommer

Growth ring analysis on silicified coniferous woods from the Missão Velha Formation (Araripe Basin - Brazil) has yielded important information about periodicity of wood production during the Early Cretaceous in the equatorial belt. Despite warm temperatures, dendrological data indicate that the climate was characterized by cyclical alternation of dry and rainy periods influenced by cyclical pre...

Journal: :Proceedings. Biological sciences 2013
Nao Kusuhashi Yukiyasu Tsutsumi Haruo Saegusa Kenji Horie Tadahiro Ikeda Kazumi Yokoyama Kazuyuki Shiraishi

We here describe a new Early Cretaceous (early Albian) eutherian mammal, Sasayamamylos kawaii gen. et sp. nov., from the 'Lower Formation' of the Sasayama Group, Hyogo Prefecture, Japan. Sasayamamylos kawaii is characterized by a robust dentary, a distinct angle on the ventral margin of the dentary at the posterior end of the mandibular symphysis, a lower dental formula of 3-4 : 1 : 4 : 3, a ro...

2007
Ah-Hwee Tan

TD-FALCON is a self-organizing neural network that incorporates Temporal Difference (TD) methods for reinforcement learning. Despite the advantages of fast and stable learning, TD-FALCON still relies on an iterative process to evaluate each available action in a decision cycle. To remove this deficiency, this paper presents a direct code access procedure whereby TD-FALCON conducts instantaneous...

Journal: :Biology letters 2012
Darren Naish Gareth Dyke Andrea Cau François Escuillié Pascal Godefroit

We describe an enormous Late Cretaceous fossil bird from Kazakhstan, known from a pair of edentulous mandibular rami (greater than 275 mm long), which adds significantly to our knowledge of Mesozoic avian morphological and ecological diversity. A suite of autapomorphies lead us to recognize the specimen as a new taxon. Phylogenetic analysis resolves this giant bird deep within Aves as a basal m...

صلواتی, مژگان, کنعانیان , علی , زعیمنیا, فاطمه , صمدی صوفی, علیرضا ,

The Southern Caspian Sea ophiolite complex (SCO) is one of the Late Cretaceous discontinuous oceanic lithosphere remnants in northern Iran. These complex is almost a complete sequence from bottom to top, ultramafic cumulates, layered gabbros, isotropic gabbros, dike complex and basaltic lavas which is covered by Late Cretaceous (Companion- maaestirchtian) pelagic limestone. Crustal ultramafic c...

2016
Gregory P. Wilson Eric G. Ekdale John W. Hoganson Jonathan J. Calede Abby Vander Linden

Marsupial mammal relatives (stem metatherians) from the Mesozoic Era (252-66 million years ago) are mostly known from isolated teeth and fragmentary jaws. Here we report on the first near-complete skull remains of a North American Late Cretaceous metatherian, the stagodontid Didelphodon vorax. Our phylogenetic analysis indicates that marsupials or their closest relatives evolved in North Americ...

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