scholarly journals A Long Mortichnial Trackway of Mesolimulus walchi from the Upper Jurassic Solnhofen Lithographic Limestone near Wintershof, Germany

2017 ◽  
Author(s):  
Dean Lomax ◽  
Christopher A. Racay

A 9.7 metre long trackway was discovered in a plattenkalk quarry near the village of Wintershof, Bavaria; Germany in 2002. The huge ichnofossil derives from the Lower Tithonian, Upper Jurassic Solnhofen Lithographic Limestone. The trackway is complete from beginning to end and consists of footprints, telson drag impressions and is identified as the ichnotaxon Kouphichnium isp. Preserved at the very end of the trackway is a complete specimen of Mesolimulus walchi confirming the trackway as a mortichnia (‘death march’). Trackways and trace makers preserved together in the fossil record are rare and such specimens allow unique insights into behaviour and ecology. The events that led to M. walchi preserved in this sediment are unknown; however a most likely scenario is that the limulid was washed into the lagoonal environment during a harsh storm.

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.


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.


Author(s):  
Mikhail A. Rogov ◽  
◽  
Julia N. Savelieva ◽  
Olga V. Shurekova ◽  
◽  
...  

The results of integrate biostratigraphic study of Upper Jurassic deposits of the clay pit near the village of Valy (Syzran district, Samara region) are presented. For the first time a bed-by-bed description was made and the subdivision of the section into zones, subzones and biohorizons by ammonites was established. Bauhini and Kitchini zones (Bayi subzone) are established in the Lower Kimeridgian, while Upper Kimmeridgian is represented by Autissiodorensis zone only. In the Lower Volgian Sokolovi and Pseudoscythica zones were recognized, while the Middle Volgian is represented by the Panderi zone. The age of the regionally developed unconformity at the base of the Trazovo Formation has been clarified. As in the sections located to the south from studied section, this unconformity is located in the base of the Autissiodorensis zone, overlying different Oxfordian and lower Kimmeridgian. For the first time for Kimmeridgian of Central Russia in the marlstone band of the Kitchini zone (bayi biohorizon) solitary corals conditionally attributed to the genus Trochocyathus were found. Along with corals other warm-water taxa (belemnites Hibolithes, rare ammonites Taramelliceras) were found in the same bed, suggesting deposition of this bed during the short-time warming event. 6 biostratigraphic units (zone and beds with fauna) were recognized by ostracods, along with 2 dinocyst-based units (assemblage and zone) which are compared with the stratigraphic subdivisions by these groups, previously proposed for the Kimeridgian and Volgian stages of the Russian Platform. The paleo-ecological analysis has allowed to assume, that sediments have accumulated in the conditions of warm shallow eutrophic basin with depth to 50 m, with gradual increase of eutrophy through time. At some levels, short-term episodes of severe shallowing or freshening are recorded by ostracods.


2013 ◽  
Vol 87 (5) ◽  
pp. 930-933 ◽  
Author(s):  
Donald R. Prothero ◽  
Brian L. Beatty ◽  
Richard M. Stucky

Simojovelhyus pocitosense is based on a lower jaw fragment with three molars from the late Oligocene amber mine deposits near the village of Simojovel, Chiapas Province, Mexico. It is the oldest fossil mammal known from Central America. It was described by Ferrusquia-Villafranca in 2006 as a helohyid, a group of primitive artiodactyls known from the Bridgerian and Uintan (older than 49–42 Ma), yet it comes from early Arikareean deposits about 25–27 Ma, suggesting that it was a very late helohyid living more than 10 m.y. after their apparent Uintan extinction. We re-examined the specimen, and compared it to the large collection of recently described peccaries from the Chadronian (Perchoerus minor) and Orellan (Perchoerus nanus) and Bridgerian helohyids (Helohyus sp.). Once the range of variation of characters in helohyids and peccaries is accounted for, Simojovelhyus shows derived similarities to early peccaries, especially in the bunodont molars with inflated cusps and the configuration of cristids and accessory cuspulids, and none of the incipient lophodonty and primitive morphology seen in helohyids. In fact, the only real similarity other than symplesiomorphies between Simojovelhyus and helohyids is its small size, but it is close to the size range of the tiny Chadronian peccary P. minor. Thus, based on both derived tooth characters and its age, it is much more parsimonious to regard Simojovelhyus as a tiny Mexican peccary from the Arikareean, not a very late helohyid. This removes the anomalously late occurrence of helohyids from the mammalian fossil record, and forces a re-examination of our view of mammalian evolution in Central America.


2000 ◽  
Vol 74 (3) ◽  
pp. 503-511 ◽  
Author(s):  
N. Bardet ◽  
M. Fernandez

Two ichthyosaurian specimens from the Upper Jurassic lithographic limestones of Bavaria, namely an almost complete skeleton with soft tissue impression and another partial one, are described for the first time. Both belong to the same taxon, which is mainly characterized by a long and slender snout; numerous small, delicate, packed, and well-anchored teeth; a medium size orbit; a reduced triangular squamosal in the cheek region; an angular largely exposed laterally reaching as far anteriorly as the surangular; a humerus with three distal facets for radius, intermedium and ulna; an extrazeugopodial element anterior to the radius; a very reduced hindlimb; packed polygonal paddle elements; and a bipartite pelvis with a distally greatly expanded puboischiatic complex. This combination of characters permits differentiation from all other known genera; moreover, it could be compared to the species inquirendae Ichthyosaurus leptospondylus Wagner, 1853a. A new genus, Aegirosaurus, is created and proposed as a new combination for this species. Aegirosaurus clearly belongs to the clade Ophthalmosauria because of an angular largely exposed laterally and reaching as far anteriorly as the surangular, and the occurrence of an extrazeugopodial element anterior to the radius and the associated digit distal to it. A systematic review of ichthyosaurs from the lithographic limestone of Bavaria (most of them destroyed during World War II) reveals the occurrence of probably three different taxa, namely Aegirosaurus, an indeterminate form close to Ophthalmosaurus or Caypullisaurus, and an indeterminate one possibly close to Nannopterygius.


2013 ◽  
Vol 44 (2) ◽  
pp. 141-147 ◽  
Author(s):  
Yan Fang ◽  
Haichun Zhang ◽  
Bo Wang ◽  
Daran Zheng

A new species of the family Prophalangopsidae, Ashanga borealis sp.n., is described from the Lower Cretaceous Yixian Fomation (Liaoning Province, P.R. China). The male forewing of the new species is similar to that of the Middle/Upper Jurassic species Ashanga clara Zherikhin 1985, but differs from it in possessing a forewing arched anterior margin, RS branching more basally, and MP + CuA1 with more branches. The fossil record of Chifengiinae is reviewed.


2007 ◽  
Vol 178 (5) ◽  
pp. 391-397 ◽  
Author(s):  
Marie-Céline Buchy ◽  
Wolfgang Stinnesbeck ◽  
Eberhard Frey ◽  
Arturo H. Gonzalez Gonzalez

Abstract The fragmentary rostrum of a thalattosuchian is described. The specimen comes from the vicinity of the village of San Juan de los Dolores, next to Los Lirios, Coahuila, northeastern Mexico. Associated ammonites allow to assign the specimen to the Kimmeridgian section (Upper Jurassic) of the La Casita Formation. Because of its massiveness, its cranial architecture and the morphology of its teeth, the specimen is referred to the genus Dakosaurus, but is too incomplete for further determination. The genus is known by few specimens from the Late Jurassic of Europe and Argentina, and was until now unknown from North and Central America. It represents a new but expected element of the assemblage of marine reptiles populating the Mexican Gulf during the Late Jurassic. The specimen is one of the few members of the group preserving in 3 dimensions and visible, the preorbital portion of the rostrum, and especially of the nasopharyngeal canal; it confirms the existence of a large space possibly housing salt glands rostral to the orbits.


2017 ◽  
Vol 129 (1) ◽  
pp. 7 ◽  
Author(s):  
Lynne B. Bean

Eastern Australia has two major Mesozoic fossil localities. The Talbragar Fish Bed in central west New South Wales contains an assemblage of Upper Jurassic fishes, plants and insects. The Koonwarra Fossil Bed, in South Gippsland, Victoria, has an assemblage of Lower Cretaceous fishes, plants and insects. The geological settings of these localities are described. Each locality has a common genus of fish that was originally described as Leptolepis. The names of both these fish have been changed, the Talbragar one to Cavenderichthys talbragarensis and the Koonwarra one to Waldmanichthys koonwarri. Both of these fish have been placed into the Family Luisiellidae, together with a Patagonian fish, Luisiella feruglioi. Each locality also has a member of the family Archaeomenidae: Archaeomene tenuis from Talbragar and Wadeichthys oxyops from Koonwarra. The relationships of these and other fish have been discussed by various authors over the last 20 years and a summary of these comments is presented, as well as a brief comparison between the plants of both localities. The localities of Talbragar, Koonwarra and the Argentinian fishes during the Mesozoic appear to have similar palaeo-environmental settings, which may explain the similarities in the assemblages. The Australian localities contain well-preserved specimens which shed light on the diversity and extent of fishes in southern Gondwana, a region otherwise poorly represented in the fossil record.


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.


Sign in / Sign up

Export Citation Format

Share Document