New insights into Lithocodium aggregatum Elliott 1956 and Bacinella irregularis Radoičić 1959 (Late Jurassic–Lower Cretaceous): two ulvophycean green algae (?Order Ulotrichales) with a heteromorphic life cycle (epilithic/euendolithic)

Facies ◽  
2010 ◽  
Vol 56 (4) ◽  
pp. 509-547 ◽  
Author(s):  
Felix Schlagintweit ◽  
Telm Bover-Arnal ◽  
Ramon Salas
Keyword(s):  
Life Cycle ◽  
Green Algae ◽  
Lower Cretaceous ◽  
Late Jurassic

New multituberculate mammal from the Early Cretaceous of eastern North America

2013 ◽  
Vol 50 (3) ◽  
pp. 315-323 ◽  
Author(s):  
Richard L. Cifelli ◽  
Cynthia L. Gordon ◽  
Thomas R. Lipka
Keyword(s):  
North America ◽  
Iberian Peninsula ◽  
Early Cretaceous ◽  
North American ◽  
Lower Cretaceous ◽  
Late Jurassic ◽  
Relative Length ◽  
Central Position ◽  
Eastern North America ◽  
The North

Multituberculates, though among the most commonly encountered mammalian fossils of the Mesozoic, are poorly known from the North American Early Cretaceous, with only one taxon named to date. Herein we describe Argillomys marylandensis, gen. et sp. nov., from the Early Cretaceous of Maryland, based on an isolated M2. Argillomys represents the second mammal known from the Arundel Clay facies of the Patuxent Formation (Lower Cretaceous: Aptian). Though distinctive in its combination of characters (e.g., enamel ornamentation consisting of ribs and grooves only, cusp formula 2:4, presence of distinct cusp on anterobuccal ridge, enlargement of second cusp on buccal row, central position of ultimate cusp in lingual row, great relative length), the broader affinities of Argillomys cannot be established because of non-representation of the antemolar dentition. Based on lack of apomorphies commonly seen among Cimolodonta (e.g., three or more cusps present in buccal row, fusion of cusps in lingual row, cusps strongly pyramidal and separated by narrow grooves), we provisionally regard Argillomys as a multituberculate of “plagiaulacidan” grade. Intriguingly, it is comparable in certain respects to some unnamed Paulchoffatiidae, a family otherwise known from the Late Jurassic – Early Cretaceous of the Iberian Peninsula.

scholarly journals New Jurassic amber outcrops from Lebanon

2013 ◽  
Vol 6 (1-2) ◽  
pp. 27-51 ◽  
Author(s):  
Youssef Nohra ◽  
Dany Azar ◽  
Raymond Gèze ◽  
Sibelle Maksoud ◽  
Antoine El-Samrani ◽  
...  
Keyword(s):  
Infrared Spectrum ◽  
Lower Cretaceous ◽  
Late Jurassic ◽  
The Past

Amber predating the Lower Cretaceous is extremely rare. During the past two decades, records of discoveries of amber sites have increased considerably worldwide. We report herein the discovery of ten new outcrops of amber from the Late Jurassic in Lebanon, in addition to other nine outcrops described by Azar et al. (2010). Some of these outcrops gave large centimetric sized amber pieces. Each of these new amber outcrops is described, and its infrared spectrum is given. Though the Jurassic amber yielded to date no more than some fungal inclusions, this discovery is significant and promising especially in the reconstruction of the paleoenvironment.

Occurrence of the ophiolitic complexes along the Indoburman orogenic belt

1983 ◽  
Vol 120 (2) ◽  
pp. 175-182 ◽  
Author(s):  
R. Duarah ◽  
M. M. Saikia ◽  
C. C. Bhattacharjee
Keyword(s):  
Upper Mantle ◽  
Deep Sea ◽  
Lower Cretaceous ◽  
Late Jurassic ◽  
Orogenic Belt ◽  
Indian Plate ◽  
Mantle Material ◽  
Crust And Upper Mantle ◽  
Thrust Sheets ◽  
Ophiolitic Belt

SummaryThe ophiolitic complexes within the Indoburman orogenic belt form a conspicuous N-S line along the eastern margins of Manipur and Nagaland. The rock assemblages consisting of mafic-ultramafics are associated with deep sea pelagic sediments of the Disang Group (Lower Cretaceous-Eocene). The ultramafics in part, represent the oceanic crust and upper mantle material that formed the basement on which the radiolarites and other pelagic sediments were deposited. The fossil radiolaria present in the cherts suggest that the orogen took its foundation during late Jurassic-Lower Cretaceous time. The westward obduction of the flysch ophiolites in the form of large thrust sheets was possible during underthrusting of the Indian plate beneath the Burmese. The position of the ophiolitic belt defines the Indoburman suture zone.

Late Palaeozoic to Early Cenozoic geological evolution of the northwestern German North Sea (Entenschnabel): New results and insights

2014 ◽  
Vol 93 (4) ◽  
pp. 147-174 ◽  
Author(s):  
Jashar Arfai ◽  
Fabian Jähne ◽  
Rüdiger Lutz ◽  
Dieter Franke ◽  
Christoph Gaedicke ◽  
...  
Keyword(s):  
North Sea ◽  
Lower Cretaceous ◽  
Late Jurassic ◽  
Structural Element ◽  
The North ◽  
Sedimentary Evolution ◽  
Basin Subsidence ◽  
The North Sea ◽  
Thickness Variations ◽  
Zechstein Salt

AbstractThe results of a detailed seismic mapping campaign of 13 horizons in the northwestern German North Sea, covering Late Permian to Palaeogene sedimentary successions, are presented. Based on the interpretation of four 3D and two 2D seismic surveys, thickness and depth maps of prominent stratigraphic units were constructed. These maps provide an overview of key structural elements, the sedimentation and erosion, and give insights into the evolution of the German Central Graben. The base of the Zechstein Group reaches a maximum depth of 7800 m within the German Central Graben. Lateral thickness variations in the Zechstein reflect the extensive mobilisation of Zechstein salt. Complex rift-related structures, with the Central Graben as the main structural element, were found not later than the Early Triassic. Up to 3000-m thick Triassic sediments are preserved in the eastern German Central Graben of which 1800 m consist of Keuper sediments. The Lower Buntsandstein unit shows increasing thicknesses towards the southeastern study area, likely related to distinct lateral subsidence. As a consequence of uplift of the North Sea Dome, Middle Jurassic sediments were eroded in large parts of the northwestern German North Sea and are only preserved in the German Central Graben. The NNW–SSE oriented John Basin is another important structural element, which shows maximum subsidence during the Late Jurassic. In most parts of the study area Lower Cretaceous sediments are absent due to either erosion or non-deposition. Lower Cretaceous deposits are preserved in the Outer Rough Basin in the northwest and within the German Central Graben. Upper Cretaceous sediments are found at depths between 1500 and 3600 m, reaching a maximum thickness of approximately 1600 m on the Schillgrund High. Contraction and inversion of pre-existing Mesozoic faults during the Late Cretaceous is distinct at the Schillgrund Fault, i.e. the eastern border fault of the Central Graben. The Palaeogene is predominantly a period of strong basin subsidence. Within 37 Myrs, up to 1400 m of Palaeogene sediments were deposited in the northwesternmost part of the study area. Detailed mapping of salt structures enables a reconstruction of halokinetic movements over time and a deciphering of the influence of the Zechstein salt on the sedimentary evolution during the Mesozoic and Cenozoic. Increasing sediment thicknesses in rim-synclines indicate that most of the salt structures in the German Central Graben had their main growth phase during the Late Jurassic.

New early Barremian amber outcrops from Lebanon

2020 ◽  
Vol 3 (6) ◽  
pp. 569-573
Author(s):  
SIBELLE MAKSOUD ◽  
KHALED TALEB ◽  
RAYMOND GÈZE ◽  
DANY AZAR
Keyword(s):  
Lower Cretaceous ◽  
Late Jurassic

Lebanon is fascinating with its numerous Mesozoic amber outcrops. To date, 19 amber outcrops have been reported from the Kimmeridgian, Late Jurassic (Azar et al., 2010b; Nohra et al., 2013; Maksoud & Azar, 2020), and more than 430 from the lower Barremian (Garnier et al., 2016; Maksoud et al., 2017), Lower Cretaceous (Maksoud & Azar, 2020). This later number is still continuously growing, with to date 24 outcrops yielding biological inclusions (Maksoud et al., 2019, 2020). Lebanese amber is among the most important ambers as it documents the initial diversification of the extant entomofauna and the disappearance of some archaic insect groups (Azar, 1997, 2007, 2012; Azar & Nel, 1998; Azar et al., 2010a; Maksoud & Azar, 2020; Poinar & Milki, 2001).

scholarly journals A comparative test of the gamete dynamics theory for the evolution of anisogamy in Bryopsidales green algae

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Tatsuya Togashi ◽  
Yusuke Horinouchi ◽  
Geoff A. Parker
Keyword(s):  
Life Cycle ◽  
Green Algae ◽  
Adult Stage ◽  
Male Gamete ◽  
Comparative Test ◽  
Disruptive Selection ◽  
Adult Size ◽  
Male Gametes ◽  
Selection For ◽  
Gamete Size

Gamete dynamics theory proposes that anisogamy arises by disruptive selection for gamete numbers versus gamete size and predicts that female/male gamete size (anisogamy ratio) increases with adult size and complexity. Evidence has been that in volvocine green algae, the anisogamy ratio correlates positively with haploid colony size. However, green algae show notable exceptions. We focus on Bryopsidales green algae. While some taxa have a diplontic life cycle in which a diploid adult (=fully grown) stage arises directly from the zygote, many taxa have a haplodiplontic life cycle in which haploid adults develop indirectly: the zygote first develops into a diploid adult (sporophyte) which later undergoes meiosis and releases zoospores, each growing into a haploid adult gametophyte. Our comparative analyses suggest that, as theory predicts: (i) male gametes are minimized, (ii) female gamete sizes vary, probably optimized by number versus survival as zygotes, and (iii) the anisogamy ratio correlates positively with diploid (but not haploid) stage complexity. However, there was no correlation between the anisogamy ratio and diploid adult stage size. Increased environmental severity (water depth) appears to drive increased diploid adult stage complexity and anisogamy ratio: gamete dynamics theory correctly predicts that anisogamy evolves with the (diploid) stage directly provisioned by the zygote.

Preferential technological and life cycle environmental performance of chitosan flocculation for harvesting of the green algae Neochloris oleoabundans

2012 ◽  
Vol 121 ◽  
pp. 445-449 ◽  
Author(s):  
Evan S. Beach ◽  
Matthew J. Eckelman ◽  
Zheng Cui ◽  
Laura Brentner ◽  
Julie B. Zimmerman
Keyword(s):  
Life Cycle ◽  
Green Algae ◽  
Environmental Performance ◽  
Neochloris Oleoabundans

Proapocritus lini sp. nov., a new ephialtitid wasp (Hymenoptera: Apocrita) from the Middle-Upper Jurassic of Daohugou, NE China

2020 ◽  
Vol 3 (1) ◽  
pp. 054-058
Author(s):  
HAICHUN ZHANG
Keyword(s):  
Lower Cretaceous ◽  
Late Jurassic ◽  
Upper Jurassic ◽  
Lower Jurassic ◽  
Ne China ◽  
Basal Group

The Ephialtitidae is an extinct family of wasps, with 29 genera reported from the Lower Jurassic-Lower Cretaceous in Kyrgyzstan, Kazakhstan, China, Mongolia, Russia, Spain, Germany and Brazil, and flourished in the Middle–Late Jurassic (Meunier, 1903; Rasnitsyn, 1975, 1977, 1990, 1999, 2008a, b; Zessin, 1981, 1985; Zhang, 1986; Darling & Sharkey, 1990; Rasnitsyn & Ansorge, 2000; Rasnitsyn & Martínez-Delclòs, 2000; Zhang et al., 2002; Rasnitsyn et al., 2003; Rasnitsyn & Zhang, 2004, 2010; Zhang et al., 2010; Ding et al., 2013, 2016; Li et al., 2013, 2014, 2015; Zhang et al., 2014). It is considered to be the most basal group of the Apocrita, one of two suborders of the order Hymenoptera (Rasnitsyn & Zhang, 2010).

The skeletal morphology of the solemydid turtleNaomichelys speciosafrom the Early Cretaceous of Texas

2014 ◽  
Vol 88 (6) ◽  
pp. 1257-1287 ◽  
Author(s):  
Walter G. Joyce ◽  
Juliana Sterli ◽  
Sandra D. Chapman
Keyword(s):  
North America ◽  
Late Cretaceous ◽  
Lower Cretaceous ◽  
Fossil Record ◽  
Posterior Margin ◽  
Late Jurassic ◽  
Evolutionary History ◽  
Ventral View ◽  
Skeletal Morphology ◽  
History Of

The fossil record of solemydid turtles is primarily based on isolated fragments collected from Late Jurassic to Late Cretaceous sediments throughout North America and Europe and little is therefore known about the morphology and evolutionary history of the group. We here provide a detailed description of the only known near-complete solemydid skeleton, which was collected from the Lower Cretaceous (Aptian–Albian) Antlers Formation of Texas during the mid-twentieth century, but essentially remains undescribed to date. Though comparison is limited, the skeleton is referred toNaomichelys speciosa, which is based on an isolated entoplastron from the Lower Cretaceous (Aptian–Albian) Kootenai (Cloverly) Formation of Montana. The absence of temporal emarginations, contribution of the jugals to the orbits, and a clear subdivision of the middle and inner cavities, and the presence of elongate postorbitals, posteriorly expanded squamosals, a triangular fossa at the posterior margin of the squamosals, an additional pair of tubercula basioccipitale that is formed by the pterygoids, foramina pro ramo nervi vidiani (VII) that are visible in ventral view, shell sculpturing consisting of high tubercles, a large entoplastron with entoplastral scute, V-shaped anterior peripherals, and limb osteoderms with tubercular sculpture diagnoseNaomichelys speciosaas a representative of Solemydidae. The full visibility of the parabasisphenoid complex in ventral view, the presence of an expanded symphyseal shelf, and the unusual ventromedial folding of the coronoid process are the primary characteristics that distinguishNaomichelys speciosafrom the near-coeval European taxonHelochelydra nopcsai.

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