New fossil Odonata from the Upper Jurassic of Bavaria with a new fossil calibration point for Zygoptera

2019 ◽  
Vol 2 (6) ◽  
pp. 618-632 ◽  
Author(s):  
GÜNTER BECHLY

Three new taxa of odonates are described from the Upper Jurassic Solnhofen limestone from Eichstätt and Painten in Bavaria (Germany), including the first two genuine Zygoptera (Andrephlebia buergeri gen. et sp. nov. in fam. inc. sed. and Jurahemiphlebia haeckeli gen. et sp. nov. in Hemiphlebiidae) and a new taxon of Stenophlebioptera (Reschiostenophlebia koschnyi gen. et sp. nov. in Stenophlebiidae). With an age of about 152 million years, the holotype of Jurahemiphlebia from the Painten locality represents the oldest fossil record and thus a new calibration point for crown group Zygoptera, Lestoidea, and Hemiphlebiidae, and the oldest record for any living odonate family. Furthermore, the first relatively complete specimen of the dragonfly Prohemeroscopus kuehnapfeli (Prohemeroscopidae) is described, which was previously known only from a pair of isolated hind wings. A revised diagnosis is provided for the species and genus.

2009 ◽  
Vol 83 (4) ◽  
pp. 562-574 ◽  
Author(s):  
Daniel B. Blake ◽  
Roger W. Portell

Oyenaster oblidus, Ocalaster timucum, and Ocalaster seloyi are new genera and species of the family Goniasteridae (Asteroidea) described from the Eocene Ocala Limestone of Florida. Although the fossil record of asteroids is sketchy, goniasterids appear to have been important contributors to marine communities since at least the Middle Jurassic. Similarities between living goniasterids and their fossil precursors indicate that plesiomorphy and convergence have been important in family history, and as a result, taxonomic interpretation is challenging. Even partial fossil goniasterids are rare, forcing systematists to rely heavily on isolated marginal ossicles, although some authors have expressed the need for caution. Building around three new taxa, we suggest that broader approaches can aid systematic interpretation of all crown-group asteroids. We also suggest that the inevitably idiosyncratic interpretations of marginal-based systematics can be partially tested using blind evaluations.


Paleobiology ◽  
2013 ◽  
Vol 39 (1) ◽  
pp. 95-108 ◽  
Author(s):  
Martin Dohrmann ◽  
Sergio Vargas ◽  
Dorte Janussen ◽  
Allen G. Collins ◽  
Gert Wörheide

Reconciliation of paleontological and molecular phylogenetic evidence holds great promise for a better understanding of the temporal succession of cladogenesis and character evolution, especially for taxa with a fragmentary fossil record and uncertain classification. In zoology, studies of this kind have largely been restricted to Bilateria. Hexactinellids (glass sponges) readily lend themselves to test such an approach for early-branching (non-bilaterian) animals: they have a long and rich fossil record, but for certain taxa paleontological evidence is still scarce or ambiguous. Furthermore, there is a lack of consensus for taxonomic interpretations, and discrepancies exist between neontological and paleontological classification systems. Using conservative fossil calibration constraints and the largest molecular phylogenetic data set assembled for this group, we infer divergence times of crown-group Hexactinellida in a Bayesian relaxed molecular clock framework. With some notable exceptions, our results are largely congruent with interpretations of the hexactinellid fossil record, but also indicate long periods of undocumented evolution for several groups. This study illustrates the potential of an integrated molecular/paleobiological approach to reconstructing the evolution of challenging groups of organisms.


2021 ◽  
Vol 79 ◽  
pp. 587-597
Author(s):  
Yan-Da Li ◽  
Erik Tihelka ◽  
Zhen-Hua Liu ◽  
Di-Ying Huang ◽  
Chen‑Yang Cai

Abstract The cryptic slime mold beetles, Sphindidae, are a moderately diverse cucujoid beetle family, whose members are obligately tied to slime molds throughout their life. The fossil record of sphindid beetles is sparse; stem-sphindids and crown-group members of uncertain systematic placement have been reported from Cretaceous ambers. Here we review the Mesozoic fossil record of Sphindidae and report a new sphindid genus and species, Trematosphindus newtonigen. et sp. nov., from Albian/Cenomanian amber from northern Myanmar (ca. 99 Ma). Trematosphindus is set apart from all other sphindids by the presence of distinct lateral cavities on the anterior pronotal angles. Our phylogenetic analysis identifies Trematosphindus as an early-diverging genus within Sphindidae, sister to the remainder of the family except Protosphindus, or Protosphindus and Odontosphindus. The new fossils provide evidence that basal crown slime mold beetles begun to diversify by the mid-Cretaceous, providing a valuable calibration point for understanding timescale of sphindid co-evolution with slime molds.


2020 ◽  
Vol 98 (12) ◽  
pp. 850-865
Author(s):  
Tetsuto Miyashita

Hagfishes and lampreys comprise cyclostomes, the earliest branching and sole surviving clade of the once diverse assemblage of jawless crown-group vertebrates. Lacking mineralized skeletons, both of the crown cyclostome lineages have notoriously poor fossil record. Particularly in the hagfish total group, †Myxinikela siroka Bardack, 1991 from the Late Carboniferous estuarine system of Illinois (USA) represents the only definitive stem taxon. Previously known from a single specimen, Myxinikela has been reconstructed as a short-bodied form with pigmented eyes but otherwise difficult to distinguish from the living counterpart. With a new, second specimen of Myxinikela reported here, I reevaluate the soft tissue anatomy and formulate diagnosis for the taxon. Myxinikela has a number of general features of cyclostomes, including cartilaginous branchial baskets, separation between the esophageal and the branchial passages, and a well-differentiated midline finfold. In effect, these features give more lamprey-like appearance to this stem hagfish than previously assumed. Myxinikela still has many traits that set modern hagfishes apart from other vertebrates (e.g., nasohypophyseal aperture, large velar cavity, and cardinal heart) and some intermediate conditions of modern hagfishes (e.g., incipient posterior displacement of branchial region). Thus, Myxinikela provides an important calibration point with which to date origins of these characters.


2014 ◽  
Vol 281 (1791) ◽  
pp. 20141470 ◽  
Author(s):  
Dirk Ahrens ◽  
Julia Schwarzer ◽  
Alfried P. Vogler

Extant terrestrial biodiversity arguably is driven by the evolutionary success of angiosperm plants, but the evolutionary mechanisms and timescales of angiosperm-dependent radiations remain poorly understood. The Scarabaeoidea is a diverse lineage of predominantly plant- and dung-feeding beetles. Here, we present a phylogenetic analysis of Scarabaeoidea based on four DNA markers for a taxonomically comprehensive set of specimens and link it to recently described fossil evidence. The phylogeny strongly supports multiple origins of coprophagy, phytophagy and anthophagy. The ingroup-based fossil calibration of the tree widely confirmed a Jurassic origin of the Scarabaeoidea crown group. The crown groups of phytophagous lineages began to radiate first (Pleurostict scarabs: 108 Ma; Glaphyridae between 101 Ma), followed by the later diversification of coprophagous lineages (crown-group age Scarabaeinae: 76 Ma; Aphodiinae: 50 Ma). Pollen feeding arose even later, at maximally 62 Ma in the oldest anthophagous lineage. The clear time lag between the origins of herbivores and coprophages suggests an evolutionary path driven by the angiosperms that first favoured the herbivore fauna (mammals and insects) followed by the secondary radiation of the dung feeders. This finding makes it less likely that extant dung beetle lineages initially fed on dinosaur excrements, as often hypothesized.


2017 ◽  
Vol 91 (4) ◽  
pp. 767-780 ◽  
Author(s):  
Jeffrey R. Thompson ◽  
Elizabeth Petsios ◽  
David J. Bottjer

AbstractThe Permian is regarded as one of the most crucial intervals during echinoid evolution because crown group echinoids are first widely known from the Permian. New faunas provide important information regarding the diversity of echinoids during this significant interval as well as the morphological characterization of the earliest crown group and latest stem group echinoids. A new fauna from the Capitanian Lamar Member of the Bell Canyon Formation in the Guadalupe Mountains of West Texas comprises at least three new taxa, includingEotiaris guadalupensisThompson n. sp. an indeterminate archaeocidarid, andPronechinus? sp. All specimens represented are silicified and known from disarticulated or semiarticulated interambulacral and ambulacral plates and spines. This assemblage is one of the most diverse echinoid assemblages known from the Permian and, as such, informs the paleoecological setting in which the earliest crown group echinoids lived. This new fauna indicates that crown group echinoids occupied the same environments as stem group echinoids of the Archaeocidaridae and Proterocidaridae. Furthermore, the echinoids described herein begin to elucidate the order of character transitions that likely took place between stem group and crown group echinoids. At least one of the morphological innovations once thought to be characteristic of early crown group echinoids, crenulate tubercles, was in fact widespread in a number of stem group taxa from the Permian as well. Crenulate tubercles are reported from two taxa, and putative cidaroid style U-shaped teeth are present in the fauna. The presence of crenulate tubercles in the archaeocidarid indicates that crenulate tubercles were present in stem group echinoids, and thus the evolution of this character likely preceded the evolution of many of the synapomorphies that define the echinoid crown group.


PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0246620
Author(s):  
Alexander Averianov ◽  
Hans-Dieter Sues

Dzharatitanis kingi gen. et sp. nov. is based on an isolated anterior caudal vertebra (USNM 538127) from the Upper Cretaceous (Turonian) Bissekty Formation at Dzharakuduk, Uzbekistan. Phylogenetic analysis places the new taxon within the diplodocoid clade Rebbachisauridae. This is the first rebbachisaurid reported from Asia and one of the youngest rebbachisaurids in the known fossil record. The caudal is characterized by a slightly opisthocoelous centrum, ‘wing-like’ transverse processes with large but shallow PRCDF and POCDF, and the absence of a hyposphenal ridge and of TPRL and TPOL. The neural spine has high SPRL, SPDL, SPOL, and POSL and is pneumatized. The apex of neural spine is transversely expanded and bears triangular lateral processes. The new taxon shares with Demandasaurus and the Wessex rebbachisaurid a high SPDL on the lateral side of the neural spine, separated from SPRL and SPOL. This possibly suggests derivation of Dzharatitanis from European rebbachisaurids. This is the second sauropod group identified in the assemblage of non-avian dinosaurs from the Bissekty Formation, in addition to a previously identified indeterminate titanosaurian.


1994 ◽  
Vol 41 ◽  
pp. 128-137
Author(s):  
John H. Callomon

􀀬e standard biochronological chronostratigraphy of the Phanerozoic and of its conjugate time-scale has been refined over a century and a half by a process of top-down subdivision in a hierarchy of successively smaller units. The finest units currently accepted, at the seventh level of the hierarchy, are the Subzones widely used in the Jurassic, thanks to that System's exceptional guide-fossils, its ammonites. But the time-resolution even at this level is not yet at the limits attainable through biostratigraphy. The ultimate observable is a characteristic fauna! horizon, defined as a fossiliferous stratum or succession of strata within whose specified fossil assemblages no further evolutionary - as opposed to compositional - changes can be dis­tinguished. Such a horizon represents effectively a biochronological instant. The fossil record is resolved into a succession of such instants, recognizable perhaps in as little as a single section and separated by time-gaps of unknown duration. The time-intervals between the ages t of successive horizons represent the limits of temporal resolution, bt, discernible by means of fossils. They depend strongly on the fossils employed and may be expressed in terms of their secular resolving-power, R = tlbt. Some estimates selected from the Mesozoic and Palaeozoic are compared in a Table. The geographical limits of time-correlation by means of fossils are often set by bioprovincial endemisms of the organisms of which the fossils are the remains. The biochronology, and any standard chronostratigraphical scale based upon it, has therefore to be worked out in each Province separately, and such provincial scales correlated in regions of provincial overlap, if known. An excellent example is found in the Middle and Upper Jurassic of East Greenland. Its ammonite biochronology is today represented by some 100 fauna! horizons. But the ammonites are largely confined to a sharply segregated Arctic, Boreal Province, for which they now provide a standard zonation. Detailed correlations with the primary standards of Europe continue to range from the problematical to the impossible.


Science ◽  
1988 ◽  
Vol 240 (4860) ◽  
pp. 1790-1790 ◽  
Author(s):  
Peter Wellnhofer

A new specimen of the primordial bird Archaeopteryx is reported from the Upper Jurassic Solnhofen Limestone of Bavaria. This "Solnhofen specimen" is the largest of now six skeletal specimens and shows dose similarities with the London specimen. It is therefore assigned to Archaeopteryx lithographica Meyer. Clear impressions of the feather shafts of the left wing are preserved.


2015 ◽  
Vol 152 (6) ◽  
pp. 1123-1136 ◽  
Author(s):  
ELADIO LIÑÁN ◽  
JOSÉ ANTONIO GÁMEZ VINTANED ◽  
RODOLFO GOZALO

AbstractThe type material ofAgraulos antiquusSdzuy, 1961 from the La Herrería Formation, northern Spain, is revised together with additional material and included in the new genusLunagraulos. The stratigraphical range ofLunagraulos antiquus(Sdzuy, 1961) – occurring below that of the trilobite species of the generaLunolenus,MetadoxidesandDolerolenusin the type locality of Los Barrios de Luna in the province of León, northern Spain – and the accompanying ichnofossil assemblage demonstrate an Ovetian age (lower part of Cambrian Stage 3, currently being discussed by the International Subcommission on Cambrian Stratigraphy) for this species. Moreover, the trilobiteLunagraulos tamamensisn. gen. n. sp. is found in the Tamames Sandstone near the village of La Rinconada in the province of Salamanca, central Spain. The biostratigraphical position of this new taxon and its accompanying ichnoassemblage is also analysed and assigned to the lowermost Ovetian Stage. The genusLunagraulosis therefore the oldest agraulid found in the fossil record. The exceptional presence ofLunagraulosin a marine coarse siliciclastic succession – a facies rather typical for the ichnofossilsCruzianaandRusophycus, some of the oldest signs of trilobite activity – suggests that first trilobite representatives may have inhabited high- to middle-energy, marine environments. This hypothesis may also explain both the taxonomic and biostratigraphic heterogeneity of the first trilobite genera appearing across the world, due to preservation problems in this type of facies. Comparison of theLunagraulos biostratigraphy with other coeval Spanish fossil assemblages allows us to propose its intercontinental correlation with the oldest records of currently known trilobites.


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