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1.
Skeletal remains of indeterminate therizinosauroid dinosaurs are present in the Cenomanian Khodzhakul Formation and common in the Turonian Bissekty Formation of Uzbekistan. At least two taxa are present in the Bissekty Formation based on different frontal and humerus morphotypes. Phylogenetic analysis based on a dataset with 348 morphological characters and including all known therizinosaurian taxa places the Bissekty taxa as derived non-therizinosaurid therizinosauroids. The Bissekty therizinosauroids are more derived than Alxasaurus elesitaiensis in the extensive pneumatization of the postcranial axial skeleton, the absence of teeth in the anterior portion of the dentary, the weak development or even absence of pits for the collateral ligaments on the manual phalanges, and the subtriangular medial aspect of the distal end of the humerus, with the entepicondyle positioned well medial to the ulnar condyle. They are less derived than Therizinosauridae in the presence of a basisphenoid recess, the absence of pneumatic openings on the anterior caudal vertebrae, the distal end of metacarpal III not being ginglymoid in dorsal view, and the separation of the femoral head from the neck of that bone by a raised ventral rim. 相似文献
2.
New ornithomimid material discovered from the Upper Cretaceous Packard Shale Formation, (Cabullona Group) of Sonora, Mexico is described. The material includes a partial skeleton, which is assigned to a new genus and species, Tototlmimus packardensis. This new taxon differs from other ornithomimids in having five unique characteristics that separate it from other Northamerican ornithomimids: (1) a distinctively articulation between metatarsals, where the distal ends of metatarsals II and IV contact directly with the distal facet of metatarsal III; (2) a metatarsal III with a weakly ginglymoid distal articular face; (3) the medial and lateral sides of metatarsal III are shaped into the form of metatarsals II and IV, so all distal ends fit together when they articulate; (4) an asymmetrical and narrow pedal ungual with shallow grooves in both medial and lateral sides; and finally, (5) the presence of a deep sulcus on the ventromedial edge, close to the articular end. Phylogenetic analysis suggests that Tototlmimus packardensis corresponds to a derived ornithomimid included in the Northamerican clade, forming a monophyly with Ornithomimus. Tototlmimus packardensis is the first definitive ornithomimid described for Mexico, and represents one of the southernmost occurrences in the Western Interior Basin of North America. 相似文献
3.
In this paper we describe previously unpublished trionychid turtle material, consisting of numerous shell fragments, from the Late Cretaceous (late Turonian) Bissekty Formation of the Dzharakuduk locality in Uzbekistan. This material is assigned to two shell-based taxa: Aspideretoides cf. riabinini and “Trionyx” cf. kansaiensis. The material which cannot be confidently attributed to these two taxa is identified as Trionychidae indet. In addition to these shell-based trionychid taxa, the Dzharakuduk turtle assemblage includes two skull-based taxa of trionychids (Khunnuchelys kizylkumensis and Trionychini indet.). The trionychids from the Bissekty Formation are most similar to trionychids from the younger (Santonian – early Campanian) Bostobe Formation of Kazakhstan, represented by three shell-based taxa (Aspideretoides riabinini, Paleotrionyx riabinini and “Trionyx” kansaiensis), and one skull-based taxon (Khunnuchelys sp.). We provide an improved understanding of the subtle similarities and differences between four closely related Cretaceous turtle assemblages of Middle Asia and Kazakhstan. 相似文献
4.
There exists a major gap in the fossil record of tyrannosauroid theropod dinosaurs spanning the early part of the Late Cretaceous. We report on skeletal remains referable to Tyrannosauroidea indet. from the Turonian Bissekty Formation at Dzharakuduk in the central Kyzylkum Desert of Uzbekistan. Phylogenetic analysis of the hypodigm places the Bissekty tyrannosauroid as a non-tyrannosaurid tyrannosauroid more basal than the Campanian tyrannosauroids Appalachiosaurus and Bistahieversor from North America. 相似文献
5.
To date three taxa of troodontid theropod dinosaurs have been recognized from Upper Cretaceous strata in two regions of the Kyzylkum Desert in Uzbekistan. The Cenomanian Khodzhakul Formation in the southwestern Kyzylkum Desert has yielded isolated serrated teeth and some postcranial bones of an indeterminate troodontid. In the central Kyzylkum Desert troodontids are known from the Cenomanian Dzharakuduk Formation (Urbacodon itemirensis) and the Turonian Bissekty Formation (Urbacodon sp.). Urbacodon itemirensis is known from a single dentary whereas Urbacodon sp. is represented by isolated teeth, maxilla and dentary fragments, a partial braincase, and some postcranial bones. The troodontid affinities of Urbacodon are supported by several synapomorphies: presence of a subotic recess; reduced basal tubera placed directly under the occipital condyle; maxilla participating in the margin of the external naris; nutrient foramina on dentary situated within a deep lateral groove; dentary without distinct interdental plates; large number of small dentary and maxillary teeth; teeth constricted between root and crown; anterior dentary teeth smaller, more numerous, more closely spaced than those in the middle of the tooth row, and implanted in a groove; posterior dorsal vertebrae with tall and posterodorsally tapering neural spines; and presence of a midline sulcus on the neural arches of distal caudals. Among Troodontidae, Urbacodon resembles Byronosaurus, Gobivenator, and Xixiasaurus in the absence of serrations on the tooth crowns and having premaxillary teeth that are D-shaped in cross-section. However, phylogenetic analysis did not recover a clade of Asiatic troodontids with unserrated teeth. 相似文献
6.
Li XuYoshitsugu Kobayashi Junchang LüYuong-Nam Lee Yongqing LiuKohei Tanaka Xingliao ZhangSonghai Jia Jiming Zhang 《Cretaceous Research》2011,32(2):213-222
A partial skeleton of the ornithomimid dinosaur, discovered from the Late Cretaceous Qiupa Formation of Luanchuan County, Tantou Basin, Henan Province, China, is described here and assigned to a new genus and species, Qiupalong henanensis, with unique features (a notch on the lateral surface of the lateral posterior process of the proximal end of tibia and a small pit at the contact between astragalus and calcaneum). A phylogenetic analysis in this study suggests that it is a derived ornithomimid and form a monophyly with North American ornithomimids (Struthiomimus altus and Ornithomimus edmontonicus), sharing two characters (straight pubic shaft and large acute angle between pubic shaft and boot). Some characters (small anterior process of the pubic boot and curved pedal unguals) are seen in basal ornithomimosaurs as well, but these features in Q. henanensis are reversal. Qiupalong is the first definitive ornithomimid from outside of the Gobi Desert and is the southern-most occurrence of Late Cretaceous ornithomimid from eastern Asia, demonstrating southern extension of ornithomimid distribution in Asia. 相似文献
7.
There are 24 known localities for skeletal remains of sauropod dinosaurs in the republics of Central Asia (Kazakhstan, Kyrgyzstan, Tajikistan, and Uzbekistan). Sauropod remains are very rare at all these localities and represented usually only by isolated teeth. Only narrow-crowned teeth are known from the Cretaceous of Central Asia. The oldest record of such teeth is from the Aptian Sultanbobo Formation of Uzbekistan. Exposures of the Turonian Bissekty Formation at the most productive vertebrate locality in the region, Dzharakuduk in Uzbekistan, has yielded many isolated teeth and a few skeletal remains that can be attributed to a non-lithostrotian titanosaur. Similar narrow-crowned, cylindrical teeth from Cenomanian-to Coniacian-age strata in the Kyzylkum Desert, Uzbekistan, may belong to a closely related taxon. Another taxon, with teeth that are pentagonal in cross-section, is known from the Santonian Yalovach and Bostobe formations of Tajikistan and western Kazakhstan, respectively. A femur reported from the Santonian Syuksyuk Formation of southern Kazakhstan possibly belongs to a lithostrotian titanosaur. The change in tooth structure at the Coniacian–Santonian boundary in the region possibly suggests replacement of non-lithostrotian titanosaurs by lithostrotians. The titanosaur from the Bissekty Formation is similar to Dongyangosaurus sinensis from the Cenomanian–Turonian of Zhejiang (China) in the extensive pneumatization of the neural arch on the anterior caudal vertebrae with several fossae. It also resembles Baotianmansaurus henanensis from the Cenomanian of Henan (China) in the possession of very short anterior caudal centra. These three taxa possibly represent an as yet formally unrecognized endemic clade of Asian non-lithostrotian titanosaurs. 相似文献
8.
In this paper we describe previously unpublished trionychid turtle material, consisting of skull fragments, from the Late Cretaceous (late Turonian) Bissekty Formation of the Dzharakuduk locality in Uzbekistan. This material is assigned to two taxa: the skull-based Khunnuchelys kizylkumensis Brinkman et al. (1993, Can. J. Earth Sci. 30, 2214-2223) and Trionychini indet. Two specimens which cannot be confidently attributed to these two taxa are considered Trionychidae indet. In addition to these trionychid taxa known from skulls, the Dzharakuduk turtle assemblage includes at least two shell-based taxa, Aspideretoides cf. A. riabinini and “Trionyx” cf. “T.” kansaiensis. For this and other Late Cretaceous localities of Middle Asia and Kazakhstan, we suggest the probable skull-shell associations of Khunnuchelys spp. with “Trionyx” kansaiensis-like forms and Trionychini indet. with Aspideretoides-like forms. 相似文献
9.
A recently discovered articulated partial skeleton of Ornithomimus from the Upper Cretaceous Dinosaur Park Formation of Alberta, Canada is remarkable in the extent and quality of preservation of integumentary structures including feathers. It is the first ornithomimid to preserve a tail bearing extensive plumaceous feathers that are slightly more elongate in comparison to those present on the remainder of the body. However, the underside of the tail and the hind limb distal to the middle of the femur appear devoid of plumage. Overall, the plumage pattern in Ornithomimus is similar to that of Struthio camelus (ostrich) and other large palaeognaths, indicating a probable function in thermoregulation. The specimen also preserves the body outline around the legs, including a skin contour anterior to the femur, analogous to skin webs in extant birds. Whereas the knee web of birds bridges the knee to the abdomen, in Ornithomimus it spans from the mid-femoral shaft to the abdomen, and is herein referred to as an anterior femoral web. This is the first report of such soft tissue structures in non-avian theropods. It may indicate that the resting position of the femur was positioned more anteroventrally in ornithomimids than in most theropods, and in that sense may have been transitional to the situation in modern birds. 相似文献
10.
A new abelisaurid theropod from the Cenomanian of Candeleros Formation (Neuquén Province, NW Patagonia, Argentina) is described. It includes an isolated frontal, partial pelvis, two fused sacral centra, femoral shaft, rib fragments, partial metatarsal II and shaft of metatarsal III. A paleohistological analysis shows that MMCh-PV 69 was somatically mature at time of death. The prevalence of relatively ordered intrinsic fibers in the primary bone indicates a relatively lower growth rate of MMCh-PV 69 compared with other abelisauroids, such as Aucasaurus garridoi. Phylogenetic analysis found MMCh-PV 69 as a basal abelisaurid, sister group of the node formed by Majungasaurinae and Brachyrostra. We estimated the body mass of MMCh-PV 69 in 240 kg, which makes it one of the smallest abelisaurids recorded. This new form adds to the extensive theropod fauna of the Candeleros Formation, probably the most diverse association of meat-eating dinosaurs recorded in a Cretaceous Formation from South America. 相似文献
11.
JI Shu''an JI Qiang School of Earth Space Sciences Peking University Beijing Institute of Geology Chinese Academy of Geological Sciences Beijing 《《地质学报》英文版》2004,78(4):897-906
The postcranial skeleton of a new specimen of the long-tailed lizard Dalinghosaurus longidigitus was excavated from the Yixian Formation in Lingyuan, western Liaoning. The new specimen provides more anatomical information about this species, especially about the anterior dorsal vertebrae, shoulder girdle and forelimbs. This lizard can be included within the clade Scleroglossa by its 27 or more presacrals, moderately long pubis, and gently notched distal end of tibia. But the detailed systematic position for this taxon remains undetermined. The features of the much longer hind limbs and pes compared with forelimbs and manus, metatarsal Ⅳ longer than Ⅲ, pedal phalanges robust, and penultimate phalanx not longer than other phalanges etc. suggest that this lizard was a running and ground swelling animal. 相似文献
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13.
Chrysoraphidia relicta gen. et sp. nov. is described from the Early Cretaceous (Barremian) of the Yixian Formation, Liaoning Province, China. Its venation is characterized by a mixture of character states that occur mainly in the Neuroptera and Raphidioptera. The assignment of Chrysoraphidia gen. nov. to Raphidioptera is supported by the presence of its distinct pterostigma and the configuration of the wing vein ‘subcosta anterior’. It is interpreted as the first record of a group of basal snakeflies (Priscaenigmatomorpha) from the Cretaceous of Asia, hitherto known only from the Early Jurassic of Europe. 相似文献
14.
Saltasaurine titanosaurs are characterized by their relatively small size compared to other sauropods, extreme postcranial pneumaticity, and dermal armour covering the body. This group has been reported in the Upper Cretaceous of the Lecho, Allen, and Anacleto formations of Argentina. We describe here a new saltasaurine specimen (MACN-Pv RN 233) from the Campanian of the Angostura Colorada Formation (Río Negro Province) that is represented by eight caudal vertebrae and six osteoderms. This specimen is described in detail and its phylogenetic relationships with the other three known saltasaurines, as well as its implications to the knowledge of caudal vertebra and osteoderm anatomy, are discussed. Our results place MACN-Pv RN 233 more closely related to Saltasaurus loricatus and Rocasaurus muniozi than to Neuquensaurus australis. MACN-Pv RN 233 possesses a combination of features that differ from other saltasaurines, but because of the fragmentary nature of the specimen we decided for the sake of taxonomic stability to not erect a new taxon. This specimen shows the first unambiguous evidence of chevron pneumatisation for a sauropodomorph, implying a broader osteological invasion of the diverticula from the abdominal air sac than previously thought for this group of dinosaurs. MACN-Pv RN 233 preserves two osteoderm morphotypes, one similar to those reported for Neuquensaurus australis and Saltasaurus loricatus. This new specimen expands the distribution of the group to a new geological unit and increases the dinosaur diversity known for the Angostura Colorada Formation. 相似文献
15.
Two new Early Cretaceous fossil rove beetle species, Paleosiagonium brevelytratum n. gen. n. sp. and Paleosiagonium adaequatum n. gen. n. sp. are described from the Lower Cretaceous Yixian Formation of Liaoning Province, China. They are clearly placed in the extant Piestinae according to the following characters: body elongate and flat; anterior coxae small and globose; abdomen long and parallel-sided, with six visible sterna and one pair of paratergites on segments III–VII. This is the first report on the occurrence of the coleopteran subfamily Piestinae in the fossil record. The new discoveries indicate that Piestinae have originated at least by the Early Cretaceous, at about 125–120 Ma. 相似文献
16.
A new genus with two new species, Orentalphila gravia gen. et sp. nov. and O. caloa sp. nov., and three new species in two known genera, Sinosciophila angustia sp. nov., Sinosciophila seboa sp. nov. and Similsciophila undulata sp. nov., are described from the Lower Cretaceous of Yixian Formation at Huangbanjigou, Beipiao City, western Liaoning, China. These new taxa, representing the first records of mesosciophilids from this locality, provide morphological information and diversity for Mesosciophilidae in the Early Cretaceous. An updated key to known genera of Mesosciophilidae is provided. In addition, according the generic diagnosis revised by Zhang, 2007, Mesoplecia antiqua Hao and Ren, 2009 should be transferred to Mesosciophila Rohdendorf, 1946. 相似文献
17.
Dean R. Lomax Judy A. Massare 《Proceedings of the Geologists' Association. Geologists' Association》2018,129(6):770-773
An incomplete forefin in the collections of the National Museum of Wales, Cardiff, is herein assigned to the rare leptonectid species, Leptonectes solei, known only from the west Dorset coast. It is only the third specimen of the species and is smaller than both the holotype and referred specimen. The new specimen is from the Lower Jurassic (lower Pliensbachian, Charmouth Mudstone Formation, Tragophylloceras ibex Ammonite Zone, Acanthopleuroceras valdani Ammonite Subzone) of Seatown, Dorset, UK. It confirms that all three species of Leptonectes were present in the Pliensbachian and expands the known diversity of ichthyosaurs for that time period. We show that isolated forefins of Leptonectes can be assigned to a species with a high degree of confidence. 相似文献
18.
Dirk Fuchs 《Proceedings of the Geologists' Association. Geologists' Association》2019,130(3-4):339-344
A concretion from the lower Tithonian Kimmeridge Clay Formation (Pectinatus Zone) found by Steve Etches yielded a gladius of a coleoid cephalopod. It is peculiar in shape and has an unusual ornamentation of radiating ribs and tubercles. The new form is named Etchesia martilli n. gen. n. sp. and preliminarily placed within the octobrachian family Muensterellidae based on its limpet-like gladius. Through the presence of radiating ribs as well as the absence of a narrow anterior rachis E. martilli n. gen. n. sp. is similar to Pearceiteuthis buyi from the Oxford Clay Formation (Callovian). The new muensterellid is unique in having an enrolled patella apex, which is located close to the posterior gladius rim. E. martilli n. gen. n. sp. represents the first muensterellid coleoid from the Kimmeridge Clay Formation. A phylogenetic relationship of E. martilli n. gen. n. sp. (and Pearceiteuthis) with cirrate and incirrate octopods is discussed, although further information on soft parts such as the muscular mantle is necessary. 相似文献
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20.
The crocodyliform faunas of the lowermost Cretaceous Rabekke and Jydegård Formations on the Baltic island of Bornholm, Denmark, and the Annero Formation of Skåne, southernmost Sweden, are represented by isolated teeth, osteoderms, and vertebrae. The rich Berriasian assemblage of the Rabekke Formation includes at least three distinctive taxa: Bernissartia sp., Theriosuchus sp., and Goniopholis sp., an association that is also known from several other contemporaneous European vertebrate localities. In contrast to this fauna, the Jydegård and Annero Formations have yielded only rare mesoeucrocodylian remains, which are assigned to Theriosuchus sp. and an undetermined mesoeucrocodylian taxon, possibly Pholidosaurus. Geographically, the Scandinavian localities represent the easternmost and northernmost distribution of typical continental Jurassic-Cretaceous crocodyliform communities in Europe. 相似文献