A Middle Triassic thoracopterid from China highlights the evolutionary origin of overwater gliding in early ray-finned fishes

Gliding adaptations in thoracopterid flying fishes represent a remarkable case of convergent evolution of overwater gliding strategy with modern exocoetid flying fishes, but the evolutionary origin of this strategy was poorly known in the thoracopterids because of lack of transitional forms. Until recently, all thoracopterids, from the Late Triassic of Austria and Italy and the Middle Triassic of South China, were highly specialized ‘four-winged’ gliders in having wing-like paired fins and an asymmetrical caudal fin with the lower caudal lobe notably larger than the upper lobe. Here, we show that the new genus Wushaichthys and the previously alleged ‘peltopleurid’ Peripeltopleurus, from the Middle Triassic (Ladinian, 235–242 Ma) of South China and near the Ladinian/Anisian boundary of southern Switzerland and northern Italy, respectively, represent the most primitive and oldest known thoracopterids. Wushaichthys, the most basal thoracopterid, shows certain derived features of this group in the skull. Peripeltopleurus shows a condition intermediate between Wushaichthys and Thoracopterus in having a slightly asymmetrical caudal fin but still lacking wing-like paired fins. Phylogenetic studies suggest that the evolution of overwater gliding of thoracopterids was gradual in nature; a four-stage adaption following the ‘cranial specialization–asymmetrical caudal fin–enlarged paired fins–scale reduction’ sequence has been recognized in thoracopterid evolution. Moreover, Wushaichthys and Peripeltopleurus bear hooklets on the anal fin of supposed males, resembling those of modern viviparious teleosts. Early thoracopterids probably had evolved a live-bearing reproductive strategy.     

The oldest ionoscopiform from China sheds new light on the early evolution of halecomorph fishes

The Halecomorphi are a major subdivision of the ray-finned fishes. Although living halecomorphs are represented solely by the freshwater bowfin, Amia calva, this clade has a rich fossil history, and the resolution of interrelationships among extinct members is central to the problem of understanding the origin of the Teleostei, the largest clade of extant vertebrates. The Ionoscopiformes are extinct marine halecomorphs that were inferred to have originated in the Late Jurassic of Europe, and subsequently dispersed to the Early Cretaceous of the New World. Here, we report the discovery of a new ionoscopiform, Robustichthys luopingensis gen. et sp. nov., based on eight well-preserved specimens from the Anisian (242–247 Ma), Middle Triassic marine deposits of Luoping, eastern Yunnan Province, China. The new species documents the oldest known ionoscopiform, extending the stratigraphic range of this group by approximately 90 Ma, and the geographical distribution of this group into the Middle Triassic of South China, a part of eastern Palaeotethys Ocean. These new data provide a minimum estimate for the split of Ionoscopiformes from its sister clade Amiiformes and shed new light on the origin of ionoscopiform fishes.     

云南中三叠世(安尼期)预言鱼目(全骨鱼类:近鲱形类)一新属种

预言鱼目是近鲱形类的一个绝灭支系,被认为是弓鳍鱼目的姐妹群.预言鱼目化石过去主要发现于欧洲的中三叠世拉丁期和晚侏罗世地层以及新大陆的早白垩世地层.近年来,在云南和贵州的中三叠世安尼期地层中分别发现了一种预言鱼目鱼类化石(强壮鱼和盘县鱼),代表了该目在中国的首次发现.根据产于云南罗平中三叠世安尼期(～244 Ma)海相地层中的6块保存良好的鱼化石,命名了预言鱼目一个新的属种,三叠复兴鱼(Subortichthys triassicus gen.et sp.nov.).三叠复兴鱼是罗平生物群中发现的第二种预言鱼目鱼类,代表了预言鱼目最古老的化石记录之一,为研究该目的起源和早期分异提供了重要信息.复兴鱼无疑可以归入近鲱形类,因为它具有近鲱形类两个共近裔性状,续骨与下颌关节以及上颌骨后缘具有凹缺.分支分析结果表明,复兴鱼位于预言鱼目的基部,因为它具有该目的重要鉴定特征,上颌骨具有感觉管,但它不具有其他预言鱼目鱼类的进步特征.特别的是,复兴鱼具有一些独特的性状,如额外肩胛骨3或4对、第三眶下骨特别宽大并与前鳃盖骨前缘相接等.复兴鱼的发现表明预言鱼目鱼类在华南地区(三叠纪时期位于古特提斯洋的东部)的早期分异至少发生在中三叠世早期(安尼期).     

Oldest coelacanth, from the Early Devonian of Australia

Coelacanths are well-known sarcopterygian (lobe-finned) fishes, which together with lungfishes are the closest extant relatives of land vertebrates (tetrapods). Coelacanths have both living representatives and a rich fossil record, but lack fossils older than the late Middle Devonian (385-390 Myr ago), conflicting with current phylogenies implying coelacanths diverged from other sarcopterygians in the earliest Devonian (410-415 Myr ago). Here, we report the discovery of a new coelacanth from the Early Devonian of Australia (407-409 Myr ago), which fills in the approximately 20 Myr 'ghost range' between previous coelacanth records and the predicted origin of the group. This taxon is based on a single lower jaw bone, the dentary, which is deep and short in form and possesses a dentary sensory pore, otherwise seen in Carboniferous and younger taxa.     

The oldest stegocephalian from the Iberian peninsula: evidence that temnospondyls were euryhaline.

The previous fossil record of limbed vertebrates of the Iberian peninsula started in the Triassic (245 Ma). The discovery of a new temnospondyl from the Late Carboniferous (Stephanian C, 290 Ma) extends the fossil record of stegocephalians in this region by at least 45 Ma. Early stegocephalians are usually thought to have been unable to live in salt water, but the new temnospondyl described below appears to have lived in a coastal region, presumably in salt water.     

New Phoenicopsis leaves (Czekanowskiales) from the Middle Jurassic Daohugou Biota,China and their roles in phytogeographic and paleoclimatic reconstruction

The Middle Jurassic Jiulongshan Formation, distributed in the Daohugou area, Ningcheng County, Inner Mongolia, China, is famous for yielding abundant, well-preserved fossil vertebrates and invertebrates. However, only a few fossil plants have been reported to date. In this paper, one new species of Czekanowskiales, Phoenicopsis (Windwardia) daohugouensis n. sp. is described based upon leaf morphology and epidermal characters. The new species represents the first record of Czekanowskiales from the Daohugou Biota. The discovery of the new species reveals the significance of the Daohugou flora as one of the deciduous forests in the temperate-warm temperate zone of Eurasia during the Middle Jurassic.     

The oldest Devonian circumpolar ray-finned fish?

Actinopterygians (ray-finned fishes) are the most diverse group of living fishes, but have a sparse Devonian fossil record restricted to low palaeolatitudes. Here we report a new actinopterygian from the Paraná Basin of Brazil, which occupied a circumpolar position in the Palaeozoic. Available geological evidence supports a Middle Devonian or older age for this taxon, which shares features of the mandibular symphysis with the latest Devonian Tegeolepis. A phylogenetic analysis resolves these two as sister taxa. This new record expands the palaeogeographic distribution of Devonian ray-fins and suggests that gaps in their fossil record might be filled by exploring poorly sampled high-latitude localities within the Malvinokaffric Realm.     

A new time-scale for ray-finned fish evolution

The Actinopterygii (ray-finned fishes) is the largest and most diverse vertebrate group, but little is agreed about the timing of its early evolution. Estimates using mitochondrial genomic data suggest that the major actinopterygian clades are much older than divergence dates implied by fossils. Here, the timing of the evolutionary origins of these clades is reinvestigated using morphological, and nuclear and mitochondrial genetic data. Results indicate that existing fossil-based estimates of the age of the crown-group Neopterygii, including the teleosts, Lepisosteus (gar) and Amia (bowfin), are at least 40 Myr too young. We present new palaeontological evidence that the neopterygian crown radiation is a Palaeozoic event, and demonstrate that conflicts between molecular and morphological data for the age of the Neopterygii result, in part, from missing fossil data. Although our molecular data also provide an older age estimate for the teleost crown, this range extension remains unsupported by the fossil evidence. Nuclear data from all relevant clades are used to demonstrate that the actinopterygian whole-genome duplication event is teleost-specific. While the date estimate of this event overlaps the probable range of the teleost stem group, a correlation between the genome duplication and the large-scale pattern of actinopterygian phylogeny remains elusive.     

Liverwort fossils from the Late Triassic of Baiyin City,Gansu Province,and their geological significance

Although liverworts are widely distributed around the world with a large number of extant species, reliable fossil records are relatively rare. Here, we report a new species, Ricciopsis baojishanensis Han and Yan, n. sp. (Ricciaceae) and an unnamed species, Hepaticites sp. from the Late Triassic Nanying’er Formation in Baojishan Basin, Baiyin City, Gansu Province, Northwest China. The generic designation is based on detailed comparison of the gross morphology with related fossil and extant species. The new species is characterized by its rosette-forming thallus, dichotomous branching, ribbon-like segments and entire margins. The current fossils represent the first record of liverwort from the Late Triassic in Baojishan Basin, Gansu Province. Based on the different fossil records of the Ricciaceae, we suggest that these taxa were widely distributed during Late Triassic to Oligocene worldwide, mainly in warm temperate and tropical environments, similar with their current distribution. The discovery of the present fossils indicates that the climate of Baojishan Basin in Late Triassic is warmer and more humid than that of today.     

A fiftieth anniversary reflection on the living coelacanth,Latimeria chalumnae: some new interpretations of its natural history and conservation status

Synopsis It all started about 400 million years ago, when representatives of a group of fish-like fleshy-finned creatures appeared in the fossil record (or was it through a childhood dream shared by all of us that we would one day study the coelacanth?). Many of the coelacanth's characters placed them close to the ancestry of terrestrial vertebrates. About 70 million years ago they disappeared from the fossil record. The discovery in 1938 of the first living coelacanth, in 1952 of the second and until now over 200 specimens parallels in excitement an encounter with a live dinosaur on a weekend walk, and in significance even more than that. For this year's 50th anniversary of the famous discovery of the first living coelacanth, we retraced the routes and visited the main actors of this zoological drama. New insights into coelacanth natural history were facilitated by novel interpretation of earlier data and our expeditions to the Comoro Islands, retracing the route of the second specimen, measuring unrecorded specimens, interviewing fishermen and describing their fishing crafts, and taking part in recent events on land and water near the only known habitat of the living coelacanth. Entry into this habitat and observations from the research submersible GEO opened up a new era in coelacanth research. Past studies of preserved specimens, which were caught as an incidental bycatch, were supplemented for the first time by studies of free-living coelacanths in their natural habitat. The first film footage taken from the submersible revealed the entirely unfishlike movements of this creature. Its mode of locomotion is a combination of flying and gliding, interspersed with head stands and belly-up drifts which appear to defy gravity. The narrow range of habitat in which the coelacanth has been encountered has led us to realize how vulnerable this ancient relict is. The members of our expeditions therefore cooperated in establishing an international organisation to coordinate efforts to conserve the coelacanth. Editorial     

A new, nearly complete stem turtle from the Jurassic of South America with implications for turtle evolution

Turtles have been known since the Upper Triassic (210Myr old); however, fossils recording the first steps of turtle evolution are scarce and often fragmentary. As a consequence, one of the main questions is whether living turtles (Testudines) originated during the Late Triassic (210Myr old) or during the Middle to Late Jurassic (ca 160Myr old). The discovery of the new fossil turtle, Condorchelys antiqua gen. et sp. nov. from the Middle to Upper Jurassic (ca 160-146Myr old) of South America (Patagonia, Argentina), presented here sheds new light on early turtle evolution. An updated cladistic analysis of turtles shows that C. antiqua and other fossil turtles are not crown turtles, but stem turtles. This cladistic analysis also shows that stem turtles were more diverse than previously thought, and that until the Middle to Upper Jurassic there were turtles without the modern jaw closure mechanism.     

A NEW SPECIES OF ALLIGATOR FROM SHANWANG, SHANDONG

<正> A crocodilian specimen is described and identified, as a new species of Alligalor in present paper. The material was collected from the Middle Member of the Shanwang Formation, Linqu County, Shandong Province by the members of the Linqu Paleontological Museum in 1984. Nearly 40 taxa of fossil vertebrates, including fishes, amphibians, reptiles, birds and mammals, have been reproted from this Miocene locality since 1930's (Yian et al. 1983, Qiu et al. 1986). Within the vertebrate fauna the fossil mammals and fishes are very rich, but the other are relatively rare. This is the first record of a crocodilan from the diatomaceous quarry of Shanwang.     

A new scanilepiform from the Lower Triassic of northern Gansu Province,China, and phylogenetic relationships of non‐teleostean Actinopterygii

A new scanilepiform, Beishanichthys brevicaudalis gen. et sp. nov. , is named and described based on fossils from the Lower Triassic lake deposits exposed in Beishan area, Gansu Province, China. The discovery documents a new record of this group, which is significantly older than other known scanilepiforms from China, and is slightly younger than Evenkia from the Lowest Triassic of Central Siberia. Although the Beishan beds were previously interpreted as Late Permian in age, based on megaplant fossils, this new discovery supports the reinterpretation of the deposits as Early Triassic in age, based on vertebrate fossils from the same locality and horizon. Phylogenetic analysis was conducted to resolve the relationships of Scanilepiformes with other actinopterygian clades, and the inter‐relationships within Scanilepiformes. Contrary to previous thought that scanilepiforms are closely related to the Amiidae, the phylogenetic results of this study recognize the Scanilepiformes as stem‐group neopterygians. Relationships of the Scanilepiformes and Australosomus with other neopterygians remain unresolved. With a characteristic long‐based dorsal fin, scanilepiforms represent a small group that emerged in Early Triassic freshwater environments, inhabited Eurasia and North America during the Middle–Late Triassic, briefly invaded the marine environment by the Late Triassic in Europe, and became extinct at the end of Triassic. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 161 , 595–612.     

The Luoping biota: exceptional preservation, and new evidence on the Triassic recovery from end-Permian mass extinction

The timing and nature of biotic recovery from the devastating end-Permian mass extinction (252 Ma) are much debated. New studies in South China suggest that complex marine ecosystems did not become re-established until the middle–late Anisian (Middle Triassic), much later than had been proposed by some. The recently discovered exceptionally preserved Luoping biota from the Anisian Stage of the Middle Triassic, Yunnan Province and southwest China shows this final stage of community assembly on the continental shelf. The fossil assemblage is a mixture of marine animals, including abundant lightly sclerotized arthropods, associated with fishes, marine reptiles, bivalves, gastropods, belemnoids, ammonoids, echinoderms, brachiopods, conodonts and foraminifers, as well as plants and rare arthropods from nearby land. In some ways, the Luoping biota rebuilt the framework of the pre-extinction latest Permian marine ecosystem, but it differed too in profound ways. New trophic levels were introduced, most notably among top predators in the form of the diverse marine reptiles that had no evident analogues in the Late Permian. The Luoping biota is one of the most diverse Triassic marine fossil Lagerstätten in the world, providing a new and early window on recovery and radiation of Triassic marine ecosystems some 10 Myr after the end-Permian mass extinction.     

Body plan convergence in the evolution of skates and rays (Chondrichthyes: Batoidea)

Skates, rays and allies (Batoidea) comprise more than half of the species diversity and much of the morphological disparity among chondrichthyan fishes, the sister group to all other jawed vertebrates. While batoids are morphologically well characterized and have an excellent fossil record, there is currently no consensus on the interrelationships of family-level taxa. Here we construct a resolved, robust and time-calibrated batoid phylogeny using mitochondrial genomes, nuclear genes, and fossils, sampling densely across taxa. Data partitioning schemes, biases in the sequence data, and the relative informativeness of each fossil are explored. The molecular phylogeny is largely congruent with morphology crownward in the tree, but the branching orders of major batoid groups are mostly novel. Body plan convergence appears to be widespread in batoids. A depressed, rounded pectoral disk supported to the snout tip by fin radials, common to skates and stingrays, is indicated to have been derived independently by each group, while the long, spiny rostrum of sawfishes similarly appears to be convergent with that of sawsharks, which are not batoids. The major extant batoid lineages are inferred to have arisen relatively rapidly from the Late Triassic into the Jurassic, with long stems followed by subsequent radiations in each group around the Cretaceous/Tertiary boundary. The fossil record indicates that batoids were affected with disproportionate severity by the end-Cretaceous extinction event.     

New fossil leaves and fruits of Lauraceae from the Middle Miocene of Fujian,southeastern China differentiated using a cluster analysis

The fossil record of Lauraceae can be traced back to the Early Cretaceous of eastern Asia based on fossil flowers. Here, we refer a number of new occurrences of leaf and fruit fossils of Lauraceae from the Middle Miocene of Zhangpu, Fujian, China, to seven species. These data provide evidence supporting the fact that a diverse subtropical, or tropical, Lauraceae-dominated evergreen forest surrounded this region 15 million years ago (Mya). The Lauraceae fossils presented in this paper provide evidence for the evolution of this group as well as new materials that enable the study of the Fujian Province Neogene flora. The fossils described in this paper fill in the gaps in studies about Lauraceae pollen in the Middle Miocene from Fotan, Fujian, China. In addition, these fossils also enrich the Middle Miocene fossil records of Lauraceae in eastern Asia, especially improving the study of the macrostructures and reproductive organs of fossil Lauraceae from southern China. The similarity between fossil and modern fruits shows that during the Middle Miocene the fruit morphological of Lauraceae have changed very little. We also identify families where the fossils we report belong to their closest relatives and can be used to reconstruct the paleoenvironment of Fujian in the Middle Miocene.     

Phylogeny of families in the Pectinoidea (Mollusca: Bivalvia): importance of the fossil record

The Triassic fossil record points to the monophyly of the Pectinoidea (scallops), all members of which have a triangular resilium with a nonmineralized medial core that functions below the hinge line. The elastic properties of this resilium in extant taxa predict that the initial adaptation of the Pectinoidea was to swimming. This is indeed corroborated by the shell form of Pernopecten , the earliest known pectinoidean genus, which ranged from late Devonian to earliest Triassic. The new family Entolioididae, a largely Triassic group, provides the missing link between the Pernopectinidae and the families Propeamussiidae, Entoliidae, and Pectinidae, all of which originated by the Middle Triassic and survive to the present day. A new Triassic genus Filamussium shows that the Propeamussiidae originated from the Entolioididae, not directly from the Pernopectinidae as previously supposed. Evidence from morphology, the fossil record, and molecular genetics indicates that the family Spondylidae originated in the Middle Jurassic from an ancestor within the Pectinidae, possibly the genus Spondylopecten , which was already present in the Late Triassic. Journal compilation © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 148 , 313–342. No claim to original US government works     

Miniaturisation and the origin of mammals

In this paper, the hypothesis of miniaturisation to explain the origin of mammals (Rowe 1993, Mammals phylogeny: mesozoic differentiation, multituberculates, monotremes, early therians, and marsupials. New York: Springer-Verlag, p. 129–145) is discussed, based on three lines of evidence resulting from new discoveries of eucynodonts in the Late Triassic of Southern Brazil (Bonaparte et al. 2003, Rev Bras Paleont 5:5–27; 2005, Rev Bras Paleont 8:25–46; 2006, New Mexico Museum Nat Hist Sci Bull 37:1–8; 2010, Rev Bras Paleont) that are: (1) the incomplete fossil record of eucynodonts known until 2003; (2) the structure of the primary palate rejects the ancestral condition of thrinaxodontids, probainognathids, chiniquodontids and cynognathids to the earliest mammals; and (3) the relatively large postdentary bones of the Middle Triassic brasilodontids that are otherwise very small in size (skull 44 mm long) suggest that small size per se did not help to improve the middle ear or other sophisticated organs present in the earliest mammals (Rowe 1993; Kemp 2005, The origin and evolution of mammals. Oxford University Press, p. 1–391). Small size possibly was not a secondary character, but a persistent primitive one. This new interpretation has resulted from comparative study of non-mammalian eucynodonts discovered in the Middle and Late Triassic of Brazil and those known previously. The general acceptance of the hypothesis of miniaturisation is thus a consequence of the poor fossil record of Middle and Late Triassic eucynodonts before 2003.     

New fossil evidence of the early diversification of scarabs: Alloioscarabaeus cheni (Coleoptera: Scarabaeoidea) from the Middle Jurassic of Inner Mongolia,China

Abstract Scarabaeoidea are known from the Lower Jurassic and may have originated in the Triassic based on fossil evidence and phylogenetic research. However, the early diversification of Scarabaeoidea remains unclear due to the lack of high‐quality fossil evidence. Here we describe an exceptionally well‐preserved new fossil of Scarabaeoidea, Alloioscarabaeus cheni gen. et sp. nov from the Middle Jurassic Jiulongshan Formation of Inner Mongolia, China. Based on a morphometric analysis using 17 landmarks of the hind wing of Alloioscarabaeus and 10 scarabaeoid families, we found that Alloioscarabaeus cheni gen. et sp. nov clearly does not belong to any of the known scarabaeoid families and, consequently, is a new family, Alloioscarabaeidae fam. nov., was erected. The discovery of Alloioscarabaeus brought further evidence for the early diversification of major scarab lineages which could allow more detail in the palaeobiogeography of the Scarabaeoidea and Northeast of China which might be one of the originating places or an important radiation place during the evolution of Scarabaeoidea. Alloioscarabaeidae were very likely not good diggers and might have fed on decaying organic materials. Based on the evidence we have now, we tend to believe that most families and some subfamilies of Scarabaeoidea were present in the Jurassic period.     

The shape of pterosaur evolution: evidence from the fossil record

Abstract Although pterosaurs are a well‐known lineage of Mesozoic flying reptiles, their fossil record and evolutionary dynamics have never been adequately quantified. On the basis of a comprehensive data set of fossil occurrences correlated with taxon‐specific limb measurements, we show that the geological ages of pterosaur specimens closely approximate hypothesized patterns of phylogenetic divergence. Although the fossil record has expanded greatly in recent years, collectorship still approximates a sigmoid curve over time as many more specimens (and thus taxa) still remain undiscovered, yet our data suggest that the pterosaur fossil record is unbiased by sites of exceptional preservation (lagerstätte). This is because as new species are discovered the number of known formations and sites yielding pterosaur fossils has also increased – this would not be expected if the bulk of the record came from just a few exceptional faunas. Pterosaur morphological diversification is, however, strongly age biased: rarefaction analysis shows that peaks of diversity occur in the Late Jurassic and Early Cretaceous correlated with periods of increased limb disparity. In this respect, pterosaurs appear unique amongst flying vertebrates in that their disparity seems to have peaked relatively late in clade history. Comparative analyses also show that there is little evidence that the evolutionary diversification of pterosaurs was in any way constrained by the appearance and radiation of birds.