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1.
The stratigraphically oldest remains of ornithomimid theropod dinosaurs are known from the Cenomanian Khodzhakul Formation and the Turonian Bissekty Formation of Uzbekistan. The ornithomimid from the Bissekty Formation is documented by more than 800 isolated bones that represent much of the skeleton. It shows at least three unambiguous synapomorphies of Ornithomimidae: length of anterior cervical centra three to five times greater than transverse width; low and rounded fibular crest of tibia; metatarsal III pinched between metatarsals II and IV; and proximal end of metatarsal III not visible in anterior view. Phylogenetic analysis, based on a dataset with 568 morphological characters and including all known ornithomimosaurian taxa, places the ornithomimid from the Bissekty Formation near the base of the ornithomimid radiation, between Archaeornithomimus asiaticus and Sinornithomimus dongi.  相似文献   

2.
In this paper we describe previously unpublished trionychid turtle material, consisting of numerous shell fragments, from the Late Cretaceous (late Turonian) Bissekty Formation of the Dzharakuduk locality in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 “Trionyxkansaiensis), 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   

3.
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   

4.
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 “Trionyxkansaiensis-like forms and Trionychini indet. with Aspideretoides-like forms.  相似文献   

5.
Megaraptoridae comprises a clade of enigmatic Gondwanan theropods with characteristic hypertrophied claws on the first and second manual digits. The majority of megaraptorids are known from South America, although a single genus (Australovenator) plus additional indeterminate material is also known from Australia. This clade has a controversial placement among theropods, and recently has been interpreted alternatively as a carcharodontosaurian or a tyrannosauroid lineage. We describe new fragmentary but associated postcranial remains from the opal fields of Lightning Ridge (middle-Albian, Griman Creek Formation) in north-central New South Wales. The new unnamed taxon exhibits a number of unusual features that suggest the presence of a hitherto unrecognised Australian megaraptorid. From an Australian perspective, the Lightning Ridge taxon predates Australovenator by ca. 10 Ma and is minimally coeval with megaraptoran material reported from the Eumeralla Formation of Victoria (but potentially 6.1–9.5 Ma younger). It is also notable as the largest predatory dinosaur yet identified from Australia and is only the second theropod known from more than a single element. A Bayesian phylogenetic approach integrating morphological, stratigraphic and palaeogeographic information tested both the carcharodontosaurian and tyrannosauroid placements for Megaraptora. Regardless of the preferred placement among Tetanurae, rigorous palaeobiogeographic analyses support an Asian origin of Megaraptora in the latest Jurassic (about 150–135 Ma), an Early Cretaceous (about 130–121 Ma) divergence of the Gondwanan lineage leading to Megaraptoridae, and an Australian root for megaraptorid radiation. These results indicate that Australia's Cretaceous dinosaur fauna did not comprise simply of immigrant taxa but was a source for complex two-way interchange between Australia–Antarctica–South America leading to the evolution of at least one group of apex predatory dinosaurs in Gondwana.  相似文献   

6.
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   

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.
There has been considerable debate about whether the controversial tyrannosauroid dinosaur ‘Nanotyrannus lancensis’ from the uppermost Cretaceous of North America is a valid taxon or a juvenile of the contemporaneous Tyrannosaurus rex. In a recent Cretaceous Research article, Schmerge and Rothschild (2016) brought a new piece of evidence to this discussion: the morphology of the dentary groove, a depression on the lateral surface of the dentary that houses neurovascular foramina. They argued that an alleged ‘Nanotyrannus’ specimen, which possesses a groove, cannot be referable to Tyrannosaurus rex, which they considered as lacking the groove, and they hypothesized that ‘Nanotyrannus’ is closely related to albertosaurine tyrannosauroids, which also are said to possess the groove. However, we show that the groove is a widespread feature of tyrannosauroids that is present in T. rex and many other specimens, and that it is an ontogenetically variable feature that changes from a sharp, deeply-impressed groove to a shallower sulcus as an individual matures. As a result, the presence or absence of a dentary groove does not clarify the validity of ‘Nanotyrannus’ or its phylogenetic position among tyrannosauroids. We consider it most parsimonious that ‘Nanotyrannus’ specimens belong to juvenile T. rex.  相似文献   

9.
Sclerogibbid wasps are obligate parasitoids of webspinners (Embiodea). Both groups have a particularly scarce geological record and are known since the Cretaceous: there are only four species of webspinners known from Burmese amber, and only two sclerogibbids were described from Barremian Lebanese and Cenomanian Burmese ambers. Here we report transferred genus from Aptian Choshi (Japan) amber and new sclerogibbids from Cenomanian Burmese and Charentese (France) ambers. The taxa described from Burmese amber are: Burmasclerogibba aptera gen. et sp. nov., Cretosclerogibba gen. nov. (with C. antennalis sp. nov., C. contractocollis sp. nov., C. neli sp. nov. and C. rasnitsyni sp. nov.) and Edrossia vetusta gen. et sp. nov. The first European fossil sclerogibbid Gallosclerogibba alnensis gen. et sp. nov. is described from Charentese amber. The holotype of Chosia yamadai Fujiyama, from Choshi amber, is re-described; it appears to be the oldest Laurasian sclerogibbid. The significant abundance and variety of Burmese sclerogibbid wasps (60% of fossil species known worldwide), as proxy of their hosts, were probably caused by the protection granted to them by the silk webs and possibly by the limited predation from ornithuromorph birds or crown-group ants. While all three extant sclerogibbid genera have apterous females, genera with winged females (Cretosclerogibba and Edrossia) dominated in Burmese amber. Small silk galleries from hosts may have favored the preservation of wings in females of Cretaceous sclerogibbids. Most new species described in the present paper, in addition to C. yamadai, are characterized by a very slender neck and a very long frontal process concealing the antennal toruli. These characters disappeared in extant species. We suggest that this loss was caused by a change in the fauna of predators, penalizing species with long neck and rostrum.  相似文献   

10.
Compared to earlier representatives of the family, pachycephalosaurids are less well known from upper Maastrichtian deposits around the world. Here, we report on a nearly complete left postorbital attributable to the pachycephalosaurid Sphaerotholus cf. Sphaerotholus buchholtzae from the upper Maastrichtian Frenchman Formation of Saskatchewan. This marks a probable northern range extension for the species into Canada, and the first occurrence of a pachycephalosaurid from this formation. We further demonstrate the taxonomic distinction between Stegoceras edmontonense and S. buchholtzae, which has been debated, based on postorbital sutural proportions. The northerly occurrence of Sphaerotholus cf. S. buchholtzae is consistent with the hypothesis of low beta diversity during the late Maastrichtian of North America, and its high stratigraphic incidence documents the persistence of non-pachycephalosaurin pachycephalosaurines in a critical interval for understanding the end-Cretaceous mass extinction event.  相似文献   

11.
A new biting midge Archiculicoides andersoni sp. nov. from Upper Cretaceous Burmese amber is described and illustrated. An unknown male of Leptoconops myanmaricus Szadziewski, 2004 is described and an undetermined female of the genus Archiaustroconops and Austroconops in the collection of National Museums Scotland is reported. A key for the determination of 10 named species in 6 genera of biting midges reported from Burmese amber is also provided.  相似文献   

12.
Four new genera and five new species of Archegocimicidae are described from the Lower Cretaceous of England: namely Mortalia martini gen. et sp. nov., Tyrion lannister gen. et sp. nov., T. cersei sp. nov., Stannis baratheon gen et sp. nov., Daenerys khaleesi gen. et sp. nov. A transitional position of the complex between Asian Late Jurassic and Early Cretaceous entomofaunas is indicated by this new material.  相似文献   

13.
Pachycephalosaurs, a group of ornithischian dinosaurs with distinctive cranial ornamentation and skull domes, underwent dramatic changes in cranial morphology during ontogeny. This has caused debate about whether some specimens belong to juveniles or adults, which impacts studies of pachycephalosaur phylogeny and evolution. One such debate concerns a small skull roof specimen from the Campanian (Upper Cretaceous) of New Mexico, NMMNH P-33898, which was originally described as an indeterminate juvenile but later regarded as a mature adult and erected as the holotype of a new small-bodied species, Stegoceras novomexicanum. We restudied NMMNH P-33898 using computed tomography scanning, morphometric and phylogenetic analyses, and comparisons to growth series of other pachycephalosaurs (Stegoceras validum, Pachycephalosaurus wyomingensis). We conclude that two purported paratype specimens of Stegoceras novomexicanum cannot be referred to the same taxon as the holotype, that the holotype and controversial paratypes all belong to immature specimens and not aberrant small-bodied adults, but that current evidence cannot clearly determine whether NMMNH P-33898 is a juvenile belonging to its own diagnostic species (S. novomexicanum) or is a juvenile of Stegoceras validum, Sphaerotholus goodwini, or another known taxon. We review the pachycephalosaur record of New Mexico and demonstrate that pachycephalosaurs were important components of dinosaur faunas in the southern part of Western North America during the ∼15 million years before the end-Cretaceous extinction, just as they were in roughly contemporaneous northern localities.  相似文献   

14.
The impact of mass extinctions on insect evolution is debated, so investigating taxa that span a crisis is important for understanding such large-scale environmental perturbations. The beetle genus Holcoptera has been found in deposits from the Late Triassic: Norian to the Early Jurassic: Sinemurian of England and the United States, and possibly Italy. Historical collections of Rev. P.B. Brodie and J.F. Jackson were re-examined and the ages of British localities reviewed, US collections were re-interpreted, and new material from the Dorset Coast was considered. Holcoptera schlotheimi and Holcoptera confluens are synonymised based on morphological similarities; Holcoptera giebeli remains distinct and a new complete specimen confirms the placement of this genus in the family Coptoclavidae. Three new species are described: Holcoptera pigmentatus sp. nov. from the Penarth Group of Warwickshire, Holcoptera alisonae sp. nov. (based on the rejected neotype of H. schlotheimi) from the Lower Lias of Dorset and Holcoptera solitensis sp. nov. from the Newark Supergroup of Virginia. H. schlotheimi and H. giebeli are known from the Late Triassic Penarth Group and Early Jurassic Lias Group and so survived the end-Triassic extinction, whereas H. alisonae and H. pigmentatus are only known from the Lias Group. H. solentensis is the oldest described species in this genus and is not known from any other locality.  相似文献   

15.
A detailed investigation of the protoglobigerinids from the Kimmeridgian section of the Montagne de Crussol, SE France is presented. This monotonous succession of predominantly carbonate beds represents peri-platform hemipelagic deposits, well dated by ammonites. Three species were determined in thin sections and in isolated forms after extraction by acetolysis. Favusella? parva (Kuznetsova) is the most common species occurring in almost the entire succession from the Orthosphinctes to the Beckeri zones. Favusella hoterivica (Subbotina) has been retrieved less frequently from the Platynota to the Beckeri zones, and it is its oldest occurrence. The rare Globuligerina bathoniana (Pazdrowa) occurs only in the Late Kimmeridgian. Based on our study and the review of the literature a palaeogeographical map was plotted, showing that most of the protoglobigerinid occurrences are in deep water facies of the northern margin and central part of the Tethys. These records demonstrate the presence of Globuligerina bathoniana, G. oxfordiana (Grigelis), Favusella hoterivica, F.? parva and Compactogerina stellapolaris (Grigelis) in the Kimmeridgian.  相似文献   

16.
The Family Afrograptidae is a ‘conchostracan’ group with multiple radial costae reaching to the umbo on their carapaces. It comprises four described genera: Afrograpta, Camerunograpta, Congestheriella and Graptoestheriella with a total of thirteen described species which are occasionally reported from the Jurassic and the Cretaceous in Africa, Europe and South America (i.e. Afrograpta from the Upper Cretaceous of Cameroon; Camerunograpta from the Jurassic to Cretaceous of Cameroon; Congestheriella from the Jurassic to Upper Cretaceous of the Congo Basin, Brazil, Bulgaria, Venezuela and Argentina; and Graptoestheriella from the Upper Jurassic to Lower Cretaceous of Brazil). A new genus and a new species, Surreyestheria ockleyensis gen. et sp. nov., belonging to the Family Afrograptidae from the Lower Cretaceous (lower Barremian) Upper Weald Clay Formation of Ockley Village, Surrey County, southern England is described in this paper. The new genus mainly differs from the other four genera by the special reticulate ornamentation on its carapace. It indicates that the Family Afrograptidae was more diverse and more widely distributed in the late Mesozoic than previously supposed. Afrograptidae is a special branch of Estheriellina the latter originating in the late Palaeozoic and the former in the early Mesozoic. Afrograptids, as a whole had been widespread across Pangea in the Early Jurassic.  相似文献   

17.
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   

18.
19.
The polychaete Janua (Dexiospira) brasiliensis (Grube) is shown to exhibit gregarious settling patterns on both natural (Zostera marina) and artificial (aquarium glass) substrates. J. (D.) brasiliensis tends to be found more often on older (=longer) Zostera blades and on the upper (=older) portions of the blades on which it is found, probably as a result of requiring a diatom mat before being able to settle on the Zostera surface. On both Zostera and the aquarium glass, J. (D.) brasiliensis forms small clumps (2 cm) with the animals within the clumps distributed at random.  相似文献   

20.
A new species belonging to the extant dermestid genus Attagenus, Attagenus burmiticus sp. nov., is described and illustrated based on a well-preserved specimen from the Upper Cretaceous Burmese amber. The discovery suggests that Attagenus is an ancient group, originating as early as in the mid-Cretaceous. Along with another species of Attagenus known from the Upper Cretaceous New Jersey amber, it implies that Attagenus were widespread in the Mesoozic.  相似文献   

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