scholarly journals Tetraliidae and Trapeziidae (Crustacea, Decapoda, Brachyura) from the Early Eocene of Monte Magrè (Vicenza, NE Italy)

2013 ◽  
Vol 154 (1) ◽  
pp. 25
Author(s):  
Antonio De Angeli ◽  
Loris Ceccon

The decapod crustaceans of the families Tetraliidae and Trapeziidae from the Early Eocene (middle-late Ypresian) of Monte Magrè (Schio, Vicenza, NE Italy), are described. The specimens are assigned to <em>Eurotetralia loerenthey</em> (Müller, 1975) n. gen., <em>Tetralia vicetina</em> n. sp. (Tetraliidae Castro, Ng &amp; Ahyong, 2004); <em>Archaeotetra lessinea</em> n. sp., <em>Eomaldivia trispinosa</em> Müller &amp; Collins, 1991, <em>Paratetralia convexa</em> Beschin, Busulini, De Angeli &amp; Tessier, 2007, and <em>Paratetralia sulcata</em> n. sp. (Trapeziidae Miers, 1886).<br />The specimens were discovered associated with other decapods, in the coral-rich limestone. This report is the oldest fossil record of both two families. The stratigraphical distribution of the Tetraliidae and Trapeziidae is extended back to the middle-late Ypresian.

Zootaxa ◽  
2020 ◽  
Vol 4838 (1) ◽  
pp. 137-142
Author(s):  
PRIYA AGNIHOTRI ◽  
KAJAL CHANDRA ◽  
ANUMEHA SHUKLA ◽  
HUKAM SINGH ◽  
RAKESH C. MEHROTRA

A fossil of a mayfly nymph that shows similarities with the modern genus Teloganella Ulmer, 1939 of the family Teloganellidae is recorded for the first time from the Indian subcontinent. It is systematically described from the Gurha lignite mine of Bikaner, Rajasthan which belongs to the Palana Formation (late Paleocene-early Eocene). As assignment of the fossil to a modern species of Teloganella is difficult due to indistinguishable location of gills in the impression, a new species, Teloganella gurhaensis Agnihotri et al., sp. nov. is instituted to include this fossil naiad resembling the extant Teloganella. 


10.4081/19 ◽  
2012 ◽  
Vol 153 (2) ◽  
pp. 257 ◽  
Author(s):  
Giovanni Pasini ◽  
Alessandro Garassino

Garassino<em> et al.</em> (2012) reported on a rich community of decapod crustaceans including axiideans, gebiideans, anomurans, and brachyurans from the Zanclean (Early Pliocene) of the “La Serra” quarry near San Miniato (Pisa, Tuscany, central Italy). In this decapod-rich assemblage some carapaces of the common pebble crab<em> Ristoria pliocaenica</em> (Ristori, 1891) (<em>Leucosiidae Samouelle</em>, 1819) are drilled in characteristic ways, due to the predatory activity of individuals belonging to two different taxa of marine clades, possibly naticids (Gastropoda, Naticoidea), and to octopodids (Cephalopoda, Octopoda). This is the first report of direct evidence of predation by cephalopods on crabs in the fossil record.


2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Giovanni Pasini ◽  
Alessandro Garassino ◽  
Marco Sami

Several specimens of anomuran and brachyuran decapods are reported from the late Pliocene clays (Argille Azzurre Fm.) at localities nearby Faenza (Ravenna, Emilia-Romagna), located in the foothills of Romagna Apennines (NE Italy). The specimens were assigned to species already reported from the Pliocene of Italy, but never previously recorded in this area. This new report enlarges our knowledge on the composition and distribution of the brachyuran decapods along the Pliocene coastline of the Adriatic Gulf of the paleo- Mediterranean Sea.


2020 ◽  
Vol 8 ◽  
Author(s):  
Grace Musser ◽  
Julia A. Clarke

The stem lineage relationships and early phenotypic evolution of Charadriiformes (shorebirds) and Gruiformes (rails, cranes, and allies) remain unresolved. It is still debated whether these clades are sister-taxa. New phylogenetic analyses incorporating Paleogene fossils have the potential to reveal the evolutionary connections of these two speciose and evolutionarily critical neoavian subclades. Although Gruiformes have a rich Paleogene fossil record, most of these fossils have not been robustly placed. The Paleogene fossil record of Charadriiformes is scarce and largely consists of fragmentary single elements. Only one proposed Eocene charadriiform-like taxon, Scandiavis mikkelseni of Denmark, is represented by a partial skeleton. Here, we describe a new species from the early Eocene Green River Formation of North America comprising a partial skeleton and feather remains. Because the skeleton lacks the pectoral girdle and forelimbs as in S. mikkelseni, only features of the skull, axial skeleton, and hind limb are available to resolve the phylogenetic placement of this taxon. These anatomical subregions initially showed features seen in Charadriiformes and Gruiformes. To assess placement of this taxon, we use a matrix consisting of 693 morphological characters and 60 taxa, including S. mikkelseni and the oldest known charadriiform taxa represented by single elements. These more fragmentary records comprise two distal humeri from the earliest Eocene Naranbulag Formation of Mongolia and the early Eocene Nanjemoy Formation of Virginia. Our phylogenetic analyses recover the new taxon and S. mikkelseni alternatively as a charadriiform or as a stem-gruiform; placement is contingent upon enforced relationships for major neoavian subclades recovered by recent molecular-based phylogenies. Specifically, when constraint trees based on results that do not recover Charadriiformes and Gruiformes as sister-taxa are used, the new taxon and S. mikkelseni are recovered within stem Gruiformes. Both Paleogene fossil humeri are consistently recovered within crown Charadriiformes. If placement of these humeri or the new taxon as charadriiforms are correct, this may indicate that recent divergence time analyses have underestimated the crown age of another major crown avian subclade; however, more complete sampling of these taxa is necessary, especially of more complete specimens with pectoral elements.


Zootaxa ◽  
2009 ◽  
Vol 2063 (1) ◽  
pp. 55-63 ◽  
Author(s):  
VLADIMIR N. MAKARKIN ◽  
S. BRUCE ARCHIBALD

A new genus and species Allorapisma chuorum gen. sp. nov. is described from the Early Eocene locality at Republic, Washington, U.S.A. The forewing venation of Allorapisma is most similar to that of the genus Principiala Makarkin & Menon from the Early Cretaceous of Brazil and Britain. A new, informal suprageneric taxon consisting of these genera is proposed, the Principiala group. The habitats of extant and fossil Ithonidae are briefly discussed.


2019 ◽  
Vol 56 (8) ◽  
pp. 803-813
Author(s):  
Gerald Mayr ◽  
S. Bruce Archibald ◽  
Gary W. Kaiser ◽  
Rolf W. Mathewes

We survey the known avian fossils from Ypresian (early Eocene) fossil sites of the North American Okanagan Highlands, mainly in British Columbia (Canada). All specimens represent taxa that were previously unknown from the Eocene of far-western North America. Wings from the McAbee site are tentatively referred to the Gaviiformes and would constitute the earliest fossil record of this group of birds. A postcranial skeleton from Driftwood Canyon is tentatively assigned to the Songziidae, a taxon originally established for fossils from the Ypresian of China. Two skeletons from Driftwood Canyon and the McAbee site are tentatively referred to Coliiformes and Zygodactylidae, respectively, whereas three further fossils from McAbee, Blakeburn, and Republic (Washington, USA) are too poorly preserved for even a tentative assignment. The specimens from the Okanagan Highlands inhabited relatively high paleoaltitudes with microthermal climates (except Quilchena: lower mesothermal) and mild winters, whereas most other Ypresian fossil birds are from much warmer lowland paleoenvironments with upper mesothermal to megathermal climates. The putative occurrence of a gaviiform bird is particularly noteworthy because diving birds are unknown from other lacustrine Ypresian fossil sites of the Northern Hemisphere. The bones of the putative zygodactylid show a sulphurous colouration, and we hypothesize that this highly unusual preservation may be due to the metabolic activity of sulphide-oxidizing bacteria.


Author(s):  
Reinhard Förster

ABSTRACTThe fossil record of unquestionable decapod remains dates back to Permo Triassic times. Evaluation of all available data from the fossil record, trace fossils and facies reveals various trends within the evolution of Mesozoic decapods, and its relation to their ecology. One of these trends is the protection of the long vulnerable abdomen. The most successful method, gradual reduction and inflection of the abdomen against the ventral cephalothorax, led to the Brachyura. Brachyurans exhibit the broadest spectrum of habitat adaptions.


1989 ◽  
Vol 63 (5) ◽  
pp. 621-626 ◽  
Author(s):  
Dale M. Tshudy ◽  
Rodney M. Feldmann ◽  
Peter D. Ward

Modern Nautilus, in natural and laboratory settings, scavenges both dead and molted decapod crustaceans. Ingestion of palinurid lobster exuviae by Nautilus follows a specific pattern in which the cephalopod consumes the exoskeleton beginning at the posteriormost part of the abdomen and continuing anteriorly. During the ingestion process, the cephalothorax is least likely to be consumed, either because the Nautilus may abandon the remains, or the cephalothorax may become separated from the abdomen at its weakest point, the articulation of the cephalothorax with the abdomen. Examination of 767 fossil lobster specimens from 50 formations, 41 of Cretaceous age, demonstrates that the fossil record of lobsters, the preponderance of which appear to be exuviae, is strongly biased in favor of cephalothoraxes. Observations on Nautilus suggest that anatomically selective scavenging by ancient cephalopods, both nautiloids and ammonoids, may explain, in part, the selective preservation of lobster cephalothoraxes over abdomens. Despite the range of variation in jaw morphologies among ammonoids, probably most could have fragmented and ingested decapod remains. Evidence for selective scavenging in the geologic past is purely circumstantial; no cephalopod bitemarks have been identified on fossil lobster exuviae. Pre-burial decomposition of connective tissues and subsequent disarticulation of the abdomen in the absence of scavenging may also have contributed significantly to the observed anatomical taphonomic bias.


2021 ◽  
Vol 17 (2) ◽  
Author(s):  
Mary T. Silcox ◽  
Keegan R. Selig ◽  
Thomas M. Bown ◽  
Amy E. Chew ◽  
Kenneth D. Rose

The early Eocene of the southern Bighorn Basin, Wyoming, is notable for its nearly continuous record of mammalian fossils. Microsyopinae (?Primates) is one of several lineages that shows evidence of evolutionary change associated with an interval referred to as Biohorizon A. Arctodontomys wilsoni is replaced by a larger species, Arctodontomys nuptus , during the biohorizon interval in what is likely an immigration/emigration or immigration/local extinction event. The latter is then superseded by Microsyops angustidens after the end of the Biohorizon A interval. Although this pattern has been understood for some time, denser sampling has led to the identification of a specimen intermediate in morphology between A. nuptus and M. angustidens , located stratigraphically as the latter is appearing. Because specimens of A. nuptus have been recovered approximately 60 m above the appearance of M. angustidens , it is clear that A. nuptus did not suffer pseudoextinction. Instead, evidence suggests that M. angustidens branched off from a population of A. nuptus , but the latter species persisted. This represents possible evidence of cladogenesis, which has rarely been directly documented in the fossil record. The improved understanding of both evolutionary transitions with better sampling highlights the problem of interpreting gaps in the fossil record as punctuations.


2003 ◽  
Vol 72 (2-3) ◽  
pp. 111-117 ◽  
Author(s):  
Rodney M. Feldmann

Decapods are the most diverse and complex group of crustaceans, adapted for life in all parts of the marine environment, many aquatic habitats, and some terrestrial niches. With this diversity of life styles, a vast range of morphotypes of decapods has evolved, exploiting almost every imaginable variation in morphology of the complex exoskeleton that characterizes them. Many of the morphological variants are a response to exploiting a particular niche in which the organisms live or an adaptation to particular behavioral characteristics. Assessing the significance of morphological variation in the fossil record is challenging because of the taphonomic overprint that results in loss of soft tissue, preservation of partial remains of hard parts, and vastly reduced numbers of preserved individuals as contrasted to the once-living population. The purpose of the present paper is to identify aspects of morphology that may be useful in interpreting the behavioral responses of the organism to its environment, with primary emphasis on morphological features of the exoskeleton that are not expressed on all individuals but that occur at low, and unpredictable, frequencies.


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