The late cretaceous flora from volcanogenic deposits of northern Priokhotie (The Okhotsk-Chukotka volcanogenic belt)

Palaeobotany ◽  
2010 ◽  
Vol 1 ◽  
pp. 45-95 ◽  
Author(s):  
S. V. Shczepetov ◽  
L. B. Golovneva

Assemblage of fossil plants from the Gydra, Yum and Kananyga Formations (the Villigha and Toomahni Rivers interfluve, Okhotsk-Chukotka volcanogenic belt) are joined in the Aleeki flora. The systematic description of main species is given and floristic and phytostratigraphical analysis of this flora is carried out. New species Lobifolia alikensis Golovn. et Shczep. is described. The Aleeki flora is typical flora of the Okhotsk-Chukotka volcanogenic belt. It contain few angiosperms and significant amount relic elements among ferns (Hausmannia, Lobifolia), cycadophytes (Heilungia), czekanowskiales (Phoenicopsis) and ginkgoales (Sphenobaiera, Ginkgo ex gr. sibirica). In consequence of its stratigraphical position the Aliky flora is slightly younger than the Chingandzha flora (the Turonian-Coniacian) and it is compositionally similar with the Chaun flora (Coniacian). On this basis the age of the Aleeki flora is estimated as the Coniacian. The common taxa of the Aleeki and Chingandzha floras are Coniopteris tschuktschorum, Asplenium dicksonianum, Cladophlebis inaequipinnulata, Birisia sp., Ginkgo ex gr. adiantoides, G. ex gr. sibirica, Sequoia, Metasequoia, Menispermites, Dalembia and Trochodendroides. The common genera of the Aleeki and Chaun floras are Coniopteris, Asplenium, Arctopteris, Cladophlebis, Ginkgo, Sphenobaiera, Heilungia, Phoenicopsis, Picea, Sequoia, Metasequoia, Menispermites, Dalembia and Trochodendroides. Besides that the Aleeki flora contains some species, which were believed as endemic of the Chaun flora: Tchaunia lobifolia, Cladophlebis grandis and Araucarites subacutensis. The Aleeki and Chaun floras are now considered as contemporaneous regional floras, which were distributed in the northern part of the Okhotsk-Chukotka volcanogenic belt.

Palaeobotany ◽  
2016 ◽  
Vol 7 ◽  
pp. 80-95 ◽  
Author(s):  
L. B. Golovneva

The Ul’ya flora comes from the Coniacian volcanogenic deposits of the Amka Formation (the Ul'ya depression, southern part of the Okhotsk-Chukotka volcanogenic belt). Ginkgoaleans are diverse in this flora and represented by three genera: Ginkgo, Sphenobaiera and Baiera. All specimens have no cuticle and were assigned to morphotaxa. Genus Ginkgo includes two species: G. ex gr. adiantoides (Ung.) Heer with entire leaves and G. ex gr. sibirica Heer with dissected leaves. Genus Sphenobaiera also consists of two species: S. ex gr. longifolia (Pom.) Florin with 4–8 leaf lobes and S. ex gr. biloba Prynada with two leaf lobes. Genus Baiera is represented by new species B. lebedevii Golovn., sp. nov.Leaves of this species are 25–30 cm long and 13–16 cm wide, narrowly wedge-shaped with flat slender petiole, dichotomously dissected 4–5 times into linear segments 3–6 mm wide with 6–12 veins. The length of ultimate segments is equal to about a half of leaf length. Leaves attached spirally to ovoid short shoots about 2 cm long. Among the Late Cretaceous floras similar diversity of ginkgoaleans was recorded only in the Turonian-Coniacian Arman flora from middle part of the Okhotsk-Chukotka volcanogenic belt (Herman et al., 2016). Four species of ginkgoaleans from the Ul’ya flora (except G. ex gr. adiantoides) are considered as the Early Cretaceous relicts.


Palaeobotany ◽  
2013 ◽  
Vol 4 ◽  
pp. 116-147 ◽  
Author(s):  
S. V. Shczepetov ◽  
A. B. Herman

Results of comprehensive study of the Kholokhovchan floral assemblage collection is summarized. These plant fossils were collected in 1978 by E. L. Lebedev from volcanogenic deposits in Penzhina and Oklan rivers interfluve, North-Eastern Russia. This assemblage was previously known as a list of Lebedev’s preliminary identifi cations only. He had suggested that the Kholokhovchan assemblage is correlative to the latest Albian — early Turonian Grebenka flora from the Anadyr River middle reaches. However, our study demonstrates that the Kholokhovchan assemblage is most similar to the presumably the Turonian-Coniacian Arman flora of the Okhotsk-Chukotka volcanogenic belt and, therefore, should be dated as the Turonian-Coniacian or Turonian.


Palaeobotany ◽  
2013 ◽  
Vol 4 ◽  
pp. 148-167 ◽  
Author(s):  
L. B. Golovneva

New investigation of fossil plants from volcanic-sedimentary deposits of the Amka Formation in Ulya River basin (southern part of the Okhotsk-Chukotka volcanogenic belt, Northeastern Russia) shows, that the Arinda, Uenma, Ust-Amka and Gyrbykan floristic assemblages from diff erent localities of this formation have very close systematic composition. We propose to joint these assemblages in the single regional flora, which is named the Ulya flora. The Ulya flora consists of almost 40 species. The majority of them are represented by new undescribed taxa. In this flora gymnosperms (Phoenicopsis ex gr. speciosa Heer, Ginkgo ex gr. adiantoides (Ung.) Heer, G. ex gr. sibirica Heer, Sphenobaiera sp., Podozamites sp., Elatocladus spp., Araucarites sp., Sequoia sp., Metasequoia sp., Cupressinocladus sp., Ditaxocladus sp., Pityophyllum sp., Pityostrobus sp.) predominate. Ferns (Asplenium dicksonianum Heer, Arctopteris sp., Cladophlebis spp. and several undescribed taxa) and angiosperms (Trochodendroides spp., undetermined Platanaceae, Dicotylophyllum spp., Quereuxia angulate (Newb.) Krysht. ex Baik.) are not abundant. This flora is characterized by presence of the Early Cretaceous relicts (Phoenicopsis, Sphenobaiera and Podozamites), by rarity of angiosperms and by high endemism. On the base of comparison of the Ulya flora with other floras from middle and northern parts of the Okhotsk-Chukotka volcanogenic belt, the age of the Ulya flora is estimated as the Coniacian.


Palaeobotany ◽  
2011 ◽  
Vol 2 ◽  
pp. 100-113 ◽  
Author(s):  
L. B. Golovneva ◽  
S. V. Shczepetov

The Karamken floristic assemblage occurs from basal layers of the Kholchan Formation of the Okchotsk-Chukotka volcanogenic belt (OCVB). The locality is situated at Khasyn River near Karamken settlement. The Karamken assemblage is composed of 6 taxa: Heilungia sp., Phoenicopsis ex gr. angustifolia Heer, Sphenobaiera sp., Metasequoia sp., Taxodium amguemensis (Efimova) Golovn., Trochodendroides sp. This flora is distinct from more ancient Arman flora and younger Ola flora. According to systematic composition the Karamken floristic assemblage is similar to the Chaun flora of Central Chukotka (the Coniacian), to the Aleeki flora from the Villigha and Toomahni Rivers interfluve (the Coniacian) and to the floristic assemblage from the Leurvaam (?) Formation of Eastern Chukotka (Efimova, 1966). On this basis the age of the Karamken flora is estimated as the Coniacian. Association of the remains of Metasequoia, Taxodium amguemensis, Phoenicopsis and large leaves of Sphenobaiera is repeated in different localities in different part of the OCVB. These remains are usually connected with fine-grained volcanogenic-terrigenous paludal-lacustrine deposits.


Palaeobotany ◽  
2014 ◽  
Vol 5 ◽  
pp. 73-93 ◽  
Author(s):  
L. B. Golovneva ◽  
S. V. Shczepetov

The Gedan floristic assemblage occurs from upper layers of the Kholchan Formation of the Okchotsk-Chukotka volcanogenic belt (OCVB). The locality is situated at the Gedan River in the middle part of the Arman River basin. The Gedan assemblage is composed of 6 taxa: Cladophlebis sp., Sphenobaiera sp., Ginkgo ex gr. adiantoides (Ung.) Heer, Taxodium amguemensis (Efimova) Golovn., Metasequoia sp., Pagiophyllum sp. The similarity of the Gedan floristic assemblage with the Karamken and the Khirumki floristic assemblages from the Kholchan Formation of the Okhotsk sector of the OCVB allows us to join them in the Kholchan flora. This flora is distinct from more ancient Arman flora, which dated as the Turonian-Coniacian and from younger Ola flora, which dated as the Santonian-early Campanian. The age of the Kholchan flora is estimated as the Coniacian on the basis of stratigraphic position, presence of Podozamites, Metasequoia and Quereuxia and also isotopic data. This flora is equivalent with the Chaun flora of Central Chukotka, with the Aleeki flora from the Villigha and Toomahni Rivers interfluve and with the Ulya flora from the southern part of the Okhotsk-Chukotka volcanogenic belt.


1984 ◽  
Vol 62 (4) ◽  
pp. 778-794 ◽  
Author(s):  
Christopher S. Lobban

From a study of living materials and specimens in several regional herbaria, a list has been drawn up of all the common and several of the rarer tube-dwelling diatoms of eastern Canada. Descriptions, illustrations of living material and acid-cleaned valves, and a key to the species are provided. Most specimens were from the Atlantic Provinces and the St. Lawrence estuary, but a few were from the Northwest Territories. By far the most common species is Berkeleya rutilans. Other species occurring commonly in the Quoddy Region of the Bay of Fundy, and sporadically in space and time elsewhere, arc Navicula delognei (two forms), Nav. pseudocomoides, Nav. smithii, Haslea crucigera, and a new species, Nav.rusticensis. Navicula ramosissima and Nav. mollis in eastern Canada are usually found as scattered cohabitants in tubes of other species. Nitzschia tubicola and Nz. fontifuga also occur sporadically as cohabitants.


2011 ◽  
Vol 83 (1) ◽  
pp. 99-108 ◽  
Author(s):  
Alexander WA. Kellner ◽  
Sergio A.K. Azevedo ◽  
Elaine B. Machado ◽  
Luciana B. de Carvalho ◽  
Deise D.R. Henriques

A new spinosaurid taxon, Oxalaia quilombensis gen. et sp. nov., is described based on the anterior part of a snout and a fragment of a maxilla. These specimens were collected at the Laje do Coringa site, Late Cretaceous (Cenomanian) of the São Luis Basin. Unlike Cristatusaurus and Suchomimus, Oxalaia quilombensis lacks serrations on the teeth. The new species differs from Angaturama limai by having the anterior part of the premaxillae more expanded and by lacking a sagittal premaxillary crest. It further differs from Spinosaurus cf. S. aegyptiacus and the Algerian spinosaurid by the rounder shape of the terminal expansion. Furthermore, xalaia quilobensis has one functional tooth followed by two replacement teeth, a feature not previously observed in theropods. Oxalaia quilombensis appears to be more closely related to the spinosaurids found in North Africa than to the Brazilian members of this clade and thus further increases the diversity of these enigmatic predatory dinosaurs in this country.


2007 ◽  
Vol 52 (3) ◽  
Author(s):  
Rodney Bray ◽  
Thomas Cribb ◽  
Andrea Waeschenbach ◽  
D. Littlewood

AbstractA new species of Acanthocolpidae, Stephanostomum adlardi is described from the serranid Plectropomus leopardus from Lizard Island in the northern Great Barrier Reef. It differs from all previously described acanthocolpids in the structure of the oral sucker which is extended into dorsal and ventral lobes each bearing a row of spines. A phylogenetic tree estimated from combined nuclear small and partial large ribosomal RNA gene sequences shows that, despite the unusual oral sucker structure, the species is a true member of the genus Stephanostomum. The molecular results also suggest that Monostephanostomum nolani is derived from within Stephanostomum.


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5594 ◽  
Author(s):  
Agustín G. Martinelli ◽  
Thiago S. Marinho ◽  
Fabiano V. Iori ◽  
Luiz Carlos B. Ribeiro

Field work conducted by the staff of the Centro de Pesquisas Paleontológicas Llewellyn Ivor Price of the Universidade Federal do Triângulo Mineiro since 2009 at Campina Verde municipality (MG) have resulted in the discovery of a diverse vertebrate fauna from the Adamantina Formation (Bauru Basin). The baurusuchidCampinasuchus diniziwas described in 2011 from Fazenda Três Antas site and after that, preliminary descriptions of a partial crocodyliform egg, abelisaurid teeth, and fish remains have been done. Recently, the fossil sample has been considerably increased including the discovery of several, partially articulated fish remains referred to Lepisosteiformes and an almost complete and articulated skeleton referred to a new species ofCaipirasuchus(Notosuchia, Sphagesauridae), which is the main subject of this contribution. At present, this genus was restricted to the Adamantina Formation cropping out in São Paulo state, with the speciesCaipirasuchus montealtensis,Caipirasuchus paulistanus, andCaipirasuchus stenognathus. The new material represents the holotype of a new species,Caipirasuchus mineirusn. sp., diferenciated from the previously ones due to the following traits: last two maxillary teeth located posterior to anterior edge of infraorbital fenestra, elongated lateroventral maxillo-jugal suture—about ½ the anteroposterior maxillar length—and contact between posterior crest of quadrate and posterior end of squamosal forming an almost 90° flaring roof of the squamosal, among others.C. mineiruswas found in the same outcrop thanCampinasuchusbut stratigraphically the former occurs in the lower portion of the section with no unambiguous data supporting the coexistance of both taxa.


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