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1.
The bathyal genus Penopus (Ophidiidae) is revised based on 23 specimens. One specimen from the Ryukyu Trench represents a new species, Penopus japonicus. The remaining 22 specimens were found on both sides of the Atlantic Ocean, and neither 28 meristic and morphometric characters nor several morphological characters show any differences between the two populations. This supports Séret (1988), who considered Penopus macdonaldi Goode and Bean 1896 a junior synonym of Penopus microphthalmus (Vaillant 1888). The new Japanese species can be separated from the Atlantic species by having fewer rays in the dorsal (117 vs. 135–158) and anal (89 vs. 106–122) fins, the squamation of the head restricted to the middle part of the preopercle versus the squamation covering the dorsum, preopercle and the opercle in part, a distinct spine behind the posterior nostril versus the spine hardly visible and 9 spines on the hind margin of the preopercle versus 4–7 spines.  相似文献   

2.
A new anthine fish, Pseudanthias calloura, is described on the basis of three specimens from Palau. The new species differs from other congeners in having a complicated color pattern of the caudal fin and the following characters: moderately forked caudal fin; dorsal fin with 10 spines, the anterior ones being shorter than the rest, and with 16 soft rays; second anal spine shorter than the third; 19 pectoral rays; scales on lateral line 51 (holotype) to 53 (paratypes) in number; tongue without teeth; circumorbital rim with several fleshy projection on posterior part; a row of fine scales occurring asymmetrically behind alternate dorsal spines on both left and right sides; preopercle margin finely serrated; interopercle and subopercle margins smooth. Received: June 9, 1999 / Revised: September 23, 2000 / Accepted: February 23, 2001  相似文献   

3.
A new perchlet, Plectranthias ryukyuensis, is described on the basis of four specimens (41.2–61.6 mm standard length: SL) from the Okinawa Islands, Japan. Plectranthias ryukyuensis can be distinguished from all congeners by the following combination of characters: X, 15 or 16 dorsal-fin rays; 14 pectoral-fin rays, all unbranched; lateral line complete, with 29 or 30 pored scales; 3 scale rows above lateral line; 5 or 6 diagonal rows of large scales on cheek between eye and corner of preopercle; preopercle with two antrorse spines on ventral margin, 20–29 serrae on posterior margin; margins of subopercle and interopercle with a few serrae (weak in large individuals); minute flaps at tips of first to ninth dorsal-fin spines; caudal fin shallowly emarginate, with some ray branches distinctively elongated past fin margin; fourth dorsal-fin spine longest, its length 110.6–128.6% that of third spine; body pinkish-white with two longitudinal rows of irregular orange-red blotches on upper half of lateral surface when fresh (rows close together in smaller than ca. 50 mm SL), blotches interconnecting anteriorly on upper and lower rows, and posterior half of lower row; four faint orange-red vertical bands below lateral line on posterior half of body and two distinct yellow blotches on cheek in fresh specimens; body uniformly yellowish-brown with two longitudinal rows of irregular dark blotches on upper half of lateral surface in preserved specimens (faint in small specimens). A key to the Japanese species of Plectranthias is given.  相似文献   

4.
The new species Grundulus quitoensis is described from El Voladero Lake, El Angel Biological Reserve, Northern Ecuador. The new taxon can be distinguished from all congeners by the following characters, respectively: a low number of unbranched rays in the anal fin (three vs. four-five) and in pectoral fins (on vs. two - three), a higher number of dentary teeth (12-14 vs. 8-10), a second infraorbital about three times larger than the first (vs. about two times larger), a third infraorbital which is not in contact with the preopercle (vs. in contact with preopercle), the presence of four small fenestrae in the infero-lateral bone dentary (vs. one - two); and a premaxilla which presents a long lateral process (vs. short), a maxilla with two notches in the infero-lateral surface (vs. one notch in the infero-lateral surface).  相似文献   

5.
Cacibupteryx caribensis gen. et sp. nov. is a new pterosaur of the family Rhamphorhynchidae found in western Cuba, in rocks of the Jagua Formation (Middle–Upper Oxfordian). The holotype, a skull and part of the left wing, is one of the few Jurassic pterosaurs that is well preserved in three dimensions. The new taxon shares characters with early and late Jurassic pterosaurs, and is one of the few late Jurassic taxa from western Laurasia and Gondwana. Furthermore, Cacibupteryx joins Nesodactylus hesperius Colbert from Cuba, and Sordes pilosus Sharov, from Kazakhstan as the most complete pterosaur recorded from the Middle–Upper Oxfordian. Cacibupteryx caribensis is one of the largest Jurassic pterosaurs known, and its skull possesses several distinct characters, including relatively broad roof elements (mainly frontal and parietal bones), a jugal with a prominent recess, occipital table trapezoidal in shape with the maximum width between the quadrate bones, and a small fenestra located in the posterior part of the pterygoid bones. In the Oxfordian, the Caribbean Corridor separated Laurasia and western Gondwana. The diversity of the marine herpetofauna found in the Jagua Vieja Member (Jagua Formation), and of teleostean fish, confirms that the corridor was an effective seaway over which flew at least Nesodactylus and Cacibupteryx .  相似文献   

6.

Background

Baurusuchidae is a group of extinct Crocodyliformes with peculiar, dog-faced skulls, hypertrophied canines, and terrestrial, cursorial limb morphologies. Their importance for crocodyliform evolution and biogeography is widely recognized, and many new taxa have been recently described. In most phylogenetic analyses of Mesoeucrocodylia, the entire clade is represented only by Baurusuchus pachecoi, and no work has attempted to study the internal relationships of the group or diagnose the clade and its members.

Methodology/Principal Findings

Based on a nearly complete skull and a referred partial skull and lower jaw, we describe a new baurusuchid from the Vale do Rio do Peixe Formation (Bauru Group), Late Cretaceous of Brazil. The taxon is diagnosed by a suite of characters that include: four maxillary teeth, supratemporal fenestra with equally developed medial and anterior rims, four laterally visible quadrate fenestrae, lateral Eustachian foramina larger than medial Eustachian foramen, deep depression on the dorsal surface of pterygoid wing. The new taxon was compared to all other baurusuchids and their internal relationships were examined based on the maximum parsimony analysis of a discrete morphological data matrix.

Conclusion

The monophyly of Baurusuchidae is supported by a large number of unique characters implying an equally large morphological gap between the clade and its immediate outgroups. A complex phylogeny of baurusuchids was recovered. The internal branch pattern suggests two main lineages, one with a relatively broad geographical range between Argentina and Brazil (Pissarrachampsinae), which includes the new taxon, and an endemic clade of the Bauru Group in Brazil (Baurusuchinae).  相似文献   

7.
Two genera and four species of discosauriscids, Discosauriscus potamites, D. pulcherrimus, Letoverpeton austriacum and L. moravicum , have previously been described from the Boskovice Furrow in Moravia. These laxa were differentiated primarily on the basis of proportional differences of the skull together with other morphological characters.
Excavations at two localities in the Boskovice Furrow have produced new, relatively abundant, skeletal material. The specimens are preserved three-dimensionally. In order to evaluate the differences in skull proportions, 17 variable characters on 70 skulls were measured. Statistical analysis demonstrates the existence of several morphological trends in the shape of the skull. However, no trend permits the division of this set of specimens into two clearly differentiated groups. The morphological differences used previously to define genera and species seem to be incorrect. Pending the discovery of distinct morphological differences, the Moravian discosauriscids can be considered as belonging to only one taxon: Discosauriscus austriacus (Makowsky, 1876).  相似文献   

8.
A fragmentary skull of a small passerine from the mid-Holocene organic-rich deposits at Florisbad, South Africa, shows a pattern of distinctive characters that allows its identification as a Cercomela chat. It resembles most closely the Familiar Chat C. familiaris and Karoo Chat C. schlegelii, which are still part of the avifauna in this part of South Africa. Furthermore, the significance of several characters of the skull for hypotheses on the phylogeny of Muscicapoidea in general, and Saxicolinae in particular, is discussed.  相似文献   

9.
A new genus and species of eutherian mammal, Acristatherium yanensis gen. et sp. nov., is described from the Early Cretaceous Jehol biota, China. The new taxon is based on a partial skull that is preserved in three dimensions from the Lujiatun bed of the Yixian Formation and dated 123.2±1.0 Ma. Its right upper and lower dentitions are nearly complete and it has a dental formula 4.1.5.3/3.1.5.3. The new mammal reveals several craniodental characteristics of Early Cretaceous eutherians previously unknown in fossil records of therians, such as a possible vestige of the septomaxilla. The craniodental features of the new taxon are compared with those of relevant Early Cretaceous eutherians and therians. Phylogenetic analyses based on a data matrix containing 70 taxa and 408 characters place A. yanensis as the most basal eutherian in the selected group. The morphological differences between Acristatherium and Eomaia indicate that eutherians already had a significant degree of generic diversification ca 125 Ma.  相似文献   

10.
11.
A new genus and species of gobiid fish,Siphonogobius nue, based on 15 specimens, is described from temperate Pacific coasts of Japan. It is unique amongst gobioids in having a simple tube-like infraorbital canal extending below the eye and the oculoscapular canal between pores A' and L' without openings, except for the terminal pores and pore D. Although well-developed infraorbital canals occur in two other gobioid genera, the rhyacichthyidRhyacichthys and the gobiidLophiogobius, such are distinct from that ofSiphonogobius in having several branches and openings. Furthermore, the new taxon is distinguished from all other gobioids by the following combination of characters: first dorsal-fin spines 7–9 (usually 8); pectoral-fin rays 24–26, the upper 7–9 rays free from the fin membrane; pelvic frenum thick, robust and slightly emarginate posteriorly; scales small and cycloid, 87–96 in longitudinal series; vertebrae 14–15+19–20=33–34 (usually 14+20=34); P-V usually 3/I II II I I I 0/11; anal-fin pterygiophores anterior to the first haemal spine 3–4 (usually 3); a row of short fleshy flaps on the ventral surface of the head, extending from the lower edge of the preopercle to the chin; anterior nostril with a minute skin flap. Axial skeletal features indicated thatSiphonogobius is closely related to a group which includesAcanthogobius and its relatives.  相似文献   

12.
Abstract:  We re-examine the type series of ' Sinemys ' wuerhoensis Yeh (at least 20 specimens, including several shells and skulls on three slabs of matrix and one isolated skull) from the Early Cretaceous Tugulu Group of China. Our study shows that the type series of ' S. ' wuerhoensis is actually a chimera made up of at least three distinct taxa. The holotype of this taxon should be assigned to the basal eucryptodire genus Xinjiangchelys Yeh. As there are no characters that distinguish ' S. ' wuerhoensis from Xinjiangchelys species, we consider it to be a nomen dubium . This new assignment of ' S. ' wuerhoensis expands the temporal range of Xinjiangchelys from the Late Jurassic into the Early Cretaceous in Asia. The majority of the paratypes of ' S. ' wuerhoensis (several shells in dorsal and ventral aspect and skulls) are referred to the basal eucryptodire genus Ordosemys Brinkman and Peng. We establish a new name for these specimens, Ordosemys brinkmania sp. nov. One additional specimen in the type series of ' S. ' wuerhoensis , a skull, is referred to cf. Pantrionychia Joyce, Parham and Gauthier indet.  相似文献   

13.
14.
The fossil salmonid †Eosalmo driftwoodensis was originally described from fragmentary specimens. Study of new material of this fossil species confirms that it is a stem-group salmonine, with a mixture of primitive and derived salmonine features in its skull, but with its postcranial skeleton essentially of modern salmonine construction. Two autapomophies define the genus †Eosalmo: a long anterodorsal process of the subopercle meeting the dorsal edge of the bone at an angle of about 60o, and a thin dermal basihyal plate apparently lacking teeth. Its salmonine relationship is supported by eight derived features: (1) posterior part of frontal widely expanded above autosphenotic, (2) hyomandibular fossa on pterotic long, (3) posterior part of endopterygoid extending posteriorly and broadly overlapped by both metapterygoid and quadrate, (4) premaxillary process of maxilla extending dorsally at an angle larger than 10o, (5) infraorbitals 3 to 5 narrow and covering less than anterior half of hyomandibula, (6) presence of suprapreopercle, (7) anterior end of preopercular canal on horizontal arm distinctiy turning to anteroventral corner of preopercle, (8) first uroneural amplified into large fan-shaped stegural, and (9) scales small, with more fhan two lateral line scales per vertebral centrum. Salmonidae are a monophyletic family defined by at least three synapomorphies: posterior surface of epiotic with sulcus, peg-and-socket connection in caudal skeleton, and tetraploid karyotype. Within the Salmonidae, Thymallinae and Salmoninae form a clade based on features from premaxilla, supramaxilla, anguloarticular, and supraorbital.  相似文献   

15.
A new exceptionally brevirostrine dyrosaurid is described from the middle Palaeocene (58–60 million years ago) Cerrejón Formation, northeastern Colombia, based on four partial skulls and associated postcrania. This taxon is unique among dyrosaurids not only in skull shape, but also in having orbital tuberosities, and osteoderms that are dorsoventrally thick and unpitted, a trait otherwise unknown in Crocodylomorpha. Results from a cladistic analysis of Dyrosauridae suggest that the new taxon, together with Cretaceous–Palaeocene Chenanisuchus lateroculi from Africa and Cerrejonisuchus improcerus also from the Cerrejón Formation, are the most basal members of the family. Results from a biogeographic analysis indicate at least three independent dispersals of dyrosaurids from Africa to the New World occurred in the Late Cretaceous or early Palaeocene. Widely set orbits in the new taxon indicate a deviation from surface-based predation, characteristic of other dyrosaurids, to sub-surface predation, as in modern Gavialis. Tooth impressions found on turtle shells recovered from the same locality match well with teeth of the new taxon indicating possible predation.http://www.zoobank.org/urn:lsid:zoobank.org:pub:AB2B24A5-27CC-4D3F-B580-F11F17851CE6  相似文献   

16.
Edenopteron keithcrooki gen. et sp. nov. is described from the Famennian Worange Point Formation; the holotype is amongst the largest tristichopterids and sarcopterygians documented by semi-articulated remains from the Devonian Period. The new taxon has dentary fangs and premaxillary tusks, features assumed to be derived for large Northern Hemisphere tristichopterids (Eusthenodon, Hyneria, Langlieria). It resembles Eusthenodon in ornament, but is distinguished by longer proportions of the parietal compared to the post-parietal shield, and numerous differences in shape and proportions of other bones. Several characters (accessory vomers in the palate, submandibulars overlapping ventral jaw margin, scales ornamented with widely-spaced deep grooves) are recorded only in tristichopterids from East Gondwana (Australia-Antarctica). On this evidence Edenopteron gen. nov. is placed in an endemic Gondwanan subfamily Mandageriinae within the Tristichopteridae; it differs from the nominal genotype Mandageria in its larger size, less pointed skull, shape of the orbits and other skull characters. The hypothesis that tristichopterids evolved in Laurussia and later dispersed into Gondwana, and a derived subgroup of large Late Devonian genera dispersed from Gondwana, is inconsistent with the evidence of the new taxon. Using oldest fossil and most primitive clade criteria the most recent phylogeny resolves South China and Gondwana as areas of origin for all tetrapodomorphs. The immediate outgroup to tristichopterids remains unresolved – either Spodichthys from Greenland as recently proposed, or Marsdenichthys from Gondwana, earlier suggested to be the sister group to all tristichopterids. Both taxa combine two characters that do not co-occur in other tetrapodomorphs (extratemporal bone in the skull; non-cosmoid round scales with an internal boss). Recently both ‘primitive’ and ‘derived’ tristichopterids have been discovered in the late Middle Devonian of both hemispheres, implying extensive ghost lineages within the group. Resolving their phylogeny and biogeography will depend on a comprehensive new phylogenetic analysis.  相似文献   

17.
Although skeletal remains of the iconic oldest known avialian Archaeopteryx have been known for almost 150 years, several aspects of the cranial anatomy of this taxon have remained enigmatic, mainly because of the strongly flattened and often fractured and incomplete nature of available skull materials. New investigation of the skulls of the recently described, excellently preserved tenth (Thermopolis) and the seventh (Munich) specimens revealed several previously unrecognized characters and helps to resolve some problematic issues. Thus, the nasal of Archaeopteryx shows a lateral notch for the lacrimal, as is found in many other saurischian dinosaurs, the maxilla clearly participates in the margin of the external nares, and there seems to be a pneumatic foramen in the lacrimal, comparable to the lacrimal fenestra found in many non-avian theropods. In the braincase, Archaeopteryx shows pneumatic features reminiscent of non-avian theropods, including a ventral basisphenoid recess and an anterior tympanic recess that is laterally incised into the basisphenoid/prootic. Most importantly, however, the postorbital process of the jugal shows a facet for the suture with the postorbital, thus resolving the question of whether Archaeopteryx had a closed postorbital bar. A new reconstruction of the skull of Archaeopteryx is presented, making the skull of this taxon even more theropod-like than previously recognized. Furthermore, the closed postorbital bar and the configuration of the bones of the skull roof cast serious doubt on claims that an avian-style cranial kinesis was present in this taxon.  相似文献   

18.
Abstract: A new fossil osteoglossid fish, Taverneichthys bikanericus gen. et sp. nov. and an unnamed but probable new species of ?Lepisosteus (Lepisosteidae) are described from the subsurface beds of the Palana (lignite) Formation near Bikaner, western Rajasthan, India. T. bikanericus is founded on a skull, which is the first osteoglossid skull from the Indian subcontinent, whereas ?Lepisosteus sp. is represented by a part of its trunk covered with ganoid scales. The taxonomic assignment of the latter specimen to gars is based on the micro‐ and ultrastructure of its scales. Taverneichthys is included in the Osteoglossinae because it shares at least three of the seven diagnostic characters of the subfamily: (1) jaw articulation behind the vertical midline of orbit, (2) palatine and ectopterygoid fused to form palato‐ectopterygoid, and (3) horizontal arm of preopercle short, ending anteriorly behind orbit (inferred). It is characterized by a considerably larger dermethmoid bone and the two nasals that are in contact with each other behind it separating this bone from the frontals. In this respect it is more evolved than Cretophareodus and Phareodus, and closer to Brychaetus, Musperia, Opsithrissops and modern osteoglossids. The fossils documented herein are the first vertebrate remains from the Palana Formation. They were recovered from a highly indurated greyish‐black calcareous shale approximately 90 m below ground level from a dug‐well section. The occurrence of fossil remains of osteoglossid and lepisosteid fish in the Palana Formation, both of which are among the major predators of a terrestrial aquatic community, and their association with the crocodilian remains, are indicative of the mature and diverse nature of the Palana vertebrate community. It postulates the recovery of a varied assemblage of vertebrates, especially fish and crocodilians and possibly also mammals. The association of osteoglossid and lepisosteid fish characterizes a dominantly freshwater deposit and is consistent with a Paleocene age for the Palana Formation. The known distribution of fossil and living osteoglossid and lepisosteid fish suggests a marked shift in their climatic adaptability in time and space. Their close association in the fossil record, especially in the Indian subcontinent, is well documented, but today they thrive in different climatic zones.  相似文献   

19.
For the first time, remains of post-Triassic temnosponyls are described from the southern Junggar Basin (NW China). Middle Jurassic material from the uppermost part of the Toutunhe Formation consists of several isolated but well preserved skull bones and intercentra from all regions of the body that can be attributed to a brachyopid. The material in part shares important autapomorphies withGobiops desertus Shishkin, 1991, from the Upper Jurassic of Outer Mongolia, and is consequently referred to this taxon, partially with reservation. This represents the first record of this genus from China. It also yields new anatomical data and permits an emended diagnosis.Ferganobatrachus from the Middle Jurassic of Kirghisia is probably, as also shown by the new material, congeneric withGobiops. Two fragmentary specimens from the lower part of the Upper Jurassic Qigu Formation are tentatively referred to the Brachyopoidea because of features of the skull, mandible and vertebral column. They probably both represent a single taxon that was larger and more massively built thanGobiops desertus but closely related to this form.   相似文献   

20.
A new artiodactyl of moderate size, Rajouria gunnelli nov. gen., nov. sp., is described on the basis of several dentaries, maxillae and isolated teeth from the middle Eocene Subathu Group of the Kalakot area, Rajouri District, Jammu and Kashmir, India. Despite its general resemblance with the family Dichobunidae by the retention of a paraconid on m1-2 and a simple P4 where endocristids do not form an anterior loph, this taxon shares with Raoellidae two unambiguous characters: the presence of a hypoconid on p4, and an asymmetrical P4. The phylogenetic position of the new taxon within the Cetacea–Raoellidae clade is strongly supported by seven non ambiguous synapomorphies, among which a cristid obliqua on lower molars anteriorly pointing towards the postectoprotocristid, and a P3 with only two roots. The presence of a new basal raoellid in the middle Eocene Subathu Group sheds new light on the phylogeny and paleobiogeography of raoellid artiodactyls.  相似文献   

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