New fossil Pinaceae from the Early Cretaceous of Mongolia

Botany ◽  
2016 ◽  
Vol 94 (9) ◽  
pp. 885-915 ◽  
Author(s):  
Fabiany Herrera ◽  
Andrew B. Leslie ◽  
Gongle Shi ◽  
Patrick Knopf ◽  
Niiden Ichinnorov ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Early Cretaceous ◽  
Distal Portion ◽  
Adaxial Surface ◽  
Anatomical Features ◽  
Central Mongolia ◽  
Seed Cone

Exceptionally well-preserved pinaceous leaves and seed cones are abundant in unconsolidated Early Cretaceous lignites in central Mongolia. These fossils include two seed cones, both of which have helically arranged bract–scale complexes with two winged seeds on the adaxial surface. The larger of the two seed cones, described as Picea farjonii sp. nov., is cylindrical to ellipsoidal, and was borne terminally on a stout shoot. The bract is small and tridentate. Leaf bases on the shoots are helically arranged, and attached leaves are linear and flattened. In all of the morphological and anatomical features that are preserved, P. farjonii is very similar to extant Picea. The smaller seed cone, described as Pityostrobus stockeyae sp. nov., shows features of several genera of extant Pinaceae. This cone is ellipsoidal and was borne terminally on a long, slender shoot. The bract is thin and triangular proximally, but the distal portion is thicker, needle-like, and deciduous. Picea farjonii and Pityostrobus stockeyae were abundant in conifer-dominated swamps in Mongolia during the Aptian–Albian and provide further support for the importance of plants related to extant Pinaceae in the vegetation of the Northern Hemisphere at this time.

scholarly journals Exceptionally well-preserved Early Cretaceous leaves of Nilssoniopteris from central Mongolia

2018 ◽  
Vol 58 (2) ◽  
pp. 135-157 ◽  
Author(s):  
Fabiany Herrera ◽  
Gongle Shi ◽  
Gombosuren Tsolmon ◽  
Niiden Ichinnorov ◽  
Masamichi Takahashi ◽  
...  
Keyword(s):  
Early Cretaceous ◽  
Direct Evidence ◽  
Leaf Surface ◽  
Insect Herbivory ◽  
Bulk Sediment ◽  
Sediment Samples ◽  
Anatomical Features ◽  
Central Mongolia ◽  
Abaxial Leaf Surface ◽  
Use Efficiency

AbstractTwo new Early Cretaceous (Aptian-Albian) species of fossil bennettitalean leaves are described from central Mongolia and assigned to the genus Nilssoniopteris. Nilssoniopteris tomentosa F.Herrera, G.Shi, Tsolmon, Ichinnorov, Takahashi, P.R.Crane, et Herend. sp. nov., isolated from bulk sediment samples collected for mesofossils in the Tevshiingovi Formation at the Tevshiin Govi opencast coal mine, is distinctive in having a dense, well-developed indumentum composed of branched, flattened multicellular trichomes on the abaxial leaf surface. This species provides the first direct evidence of complex multicellular trichomes in Bennettitales and adds to the evidence of leaf anatomical features in the group that were probably advantageous in increasing water use efficiency and/or perhaps had other functions such as deterring insect herbivory. Comparison with other well-preserved leaves of Bennettitales, including Nilssoniopteris shiveeovoensis F.Herrera, G.Shi, Tsolmon, Ichinnorov, Takahashi, P.R.Crane, et Herend. sp. nov., collected as hand specimens from the Khukhteeg Formation at the Shivee Ovoo locality, suggests that the trichome bases seen commonly on the abaxial cuticle of bennettitalean leaves bore trichomes with very low fossilization potential. In some cases these trichomes may have been shed as the leaves matured, but in other cases they probably decayed during diagenesis or were destroyed during the standard processes by which fossil leaf cuticles are prepared.

Mesocyparis borealis gen. et sp. nov.: fossil Cupressaceae from the early Tertiary of Saskatchewan, Canada

1987 ◽  
Vol 65 (11) ◽  
pp. 2338-2351 ◽  
Author(s):  
E. E. McIver ◽  
J. F. Basinger
Keyword(s):  
Northern Hemisphere ◽  
Branching Pattern ◽  
Natural Group ◽  
Classification Schemes ◽  
Cone Structure ◽  
Reproductive Morphology ◽  
Extant Genus ◽  
Early Tertiary ◽  
Seed Cone ◽  
First Time

Fossil cedar foliage of the Cupressinocladus interruptus type, with associated seeds and cones, is locally abundant in Paleocene deposits of the Ravenscrag Formation, southwestern Saskatchewan, Canada. Vegetative remains of this type occur frequently in early Tertiary plant assemblages throughout the northern hemisphere, indicating that this now extinct cedar was once widespread. For the first time this cedar can be described on the basis of both vegetative and reproductive morphology. Foliage is frond-like with a characteristic opposite branching pattern. Seed cones are globose and woody and bear four equal and decussate scales with prominent umbos. Seeds bear large, equal, semicircular wings. The fossil cedar appears most closely related to extant Cupressaceae such as Thuja, Chamaecyparis, and Heyderia. Foliage closely resembles that of Thuja, while cones are most similar to those of Chamaecyparis. The fossil differs sufficiently in foliage and seed cone structure to preclude assignment to an extant genus and is here assigned to Mesocyparis borealis gen. et sp. nov. Similarities among such extant genera as Thuja, Chamaecyparis, Heyderia, and Thujopsis and the fossil Mesocyparis borealis suggest that all may belong to a single natural group. Furthermore, this group may be more closely related to the southern hemispheric genera Libocedrus, Papuacedrus, and Austrocedrus than present classification schemes imply. Our examination of the Cupressaceae indicates that a revision of present systems of classification is required to accommodate evidence from both extant and extinct cedars.

scholarly journals Revision of rock fossils of Dryinidae and Embolemidae (Hymenoptera: Chrysidoidea)

Zootaxa ◽  
2010 ◽  
Vol 2499 (1) ◽  
pp. 21 ◽  
Author(s):  
MASSIMO OLMI ◽  
ALEXANDER P. RASNITSYN ◽  
ADALGISA GUGLIELMINO
Keyword(s):  
Early Cretaceous ◽  
Upper Cretaceous ◽  
Middle Miocene ◽  
Russian Far East ◽  
Far East ◽  
Left Bank ◽  
Rock Unit ◽  
Central Mongolia ◽  
Lake Deposits ◽  
Maritime Province

New fossil taxa of Embolemidae and Dryinidae (Hymenoptera: Chrysidoidea) are described. For Embolemidae, Embolemopsis baissensis n. gen. n. sp. and Baissobius minutus n. sp., are described from Central Siberia, West Transbaikalia, left bank of Vitim River (facing downstream), Baissa, lake deposits from earlier Early Cretaceous (Neocomian stage) (130–140 mybp). For Dryinidae, Anteonopsis antiquus n. gen. n. sp., Bocchus ? cenomanianus n. sp. and Gonatopus ? cretacicus n. sp., are described from Siberia, Magadan Region, Obeschchayushchiyi, tuffaceous deposits from Upper Cretaceous (Cenomanian) (90–95 mybp); Deinodryinus ? aptianus n. sp., is described from Central Mongolia, Bayanhongor Aimag, 5–8 Km N Bon Tsagan Nuur Lake, from impressed in lake deposits of the Khurilt rock unit probably of Aptian (Early Cretaceous) (100–115 mybp). In addition, an unidentified fossil belonging to Deinodryinus ? or Dryinus ? is recorded from Russian Far East, Maritime Province, Velikaya Kema (later Earlier or early Middle Miocene) (about 30 mybp). The known species of Baissobius Rasnitsyn are reviewed and a key is presented.

DEVELOPMENT OF THE SEED CONE OF DOUGLAS-FIR FOLLOWING DORMANCY

1965 ◽  
Vol 43 (2) ◽  
pp. 317-332 ◽  
Author(s):  
John N. Owens ◽  
Frank H. Smith
Keyword(s):  
Early Development ◽  
Maximum Size ◽  
Developmental Cycle ◽  
Surface Layers ◽  
Adaxial Surface ◽  
Single Leaf ◽  
Separate Branch ◽  
Cycle Growth ◽  
Seed Cone ◽  
Lateral Shoots

Development of the megasporangiate cone during the period of enlargement and maturation following dormancy is described in detail. This work, in conjunction with the early development previously described, provides a complete description of the 17 month developmental cycle. Growth of the megasporangiate cone is resumed in early March near Corvallis, Oregon, and the cone buds burst about 1 month later. The cone elongates rapidly by intercalary growth. Bracts enlarge but the shape of the bract established prior to dormancy is essentially maintained. The scale assumes a spoon-shaped appearance as a result of a form of marginal growth. Vascularization, and development of other tissues within the bract and scale, indicates that bracts are homologous to leaves and basically similar in structure, but scales are highly modified fertile lateral shoots. Each bract is supplied by a single leaf trace and each scale by two separate branch traces. The seed wings differentiate from adaxial surface layers of each scale. A large zone of macrosclereids differentiates in the basal abaxial portion of the scale. The cone reaches its maximum size early in July and maturation of tissues occurs in July and August, and is generally complete early in September. Cone opening results from drying and shrinkage of the macrosclereids at the base of the scale.

What Iberian dinosaurs reveal about the bridge said to exist between Gondwana and Laurasia in the Early Cretaceous

2009 ◽  
Vol 180 (1) ◽  
pp. 5-11 ◽  
Author(s):  
José Ignacio Canudo ◽  
José Luis Barco ◽  
Xabier Pereda-Suberbiola ◽  
José Ignacio Ruiz-Omeñaca ◽  
Leonardo Salgado ◽  
...  
Keyword(s):  
Iberian Peninsula ◽  
Northern Hemisphere ◽  
Early Cretaceous ◽  
Late Jurassic ◽  
Open Ocean ◽  
Early Jurassic ◽  
Place Of Origin ◽  
Iberian Margin ◽  
Great Development ◽  
Iberian Plate

Abstract Some Cretaceous dinosaur taxa with a broad enough record on the continents of the northern hemisphere (Laurasia) or in the southern continents (Gondwana) have been interpreted as Laurasian or Gondwanan in origin. The occasional presence of these taxa outside Laurasia or Gondwana respectively has frequently been explained in terms of dispersal from their place of origin by means of land bridges that are indeterminate in location and character. One example of such a dispersal event is provided by the Early Cretaceous dinosaurs of Europe and Africa. Certain European taxa have been interpreted as having their origin in Gondwana. If we regard these presences common to both areas as being the result of a point of communication between Laurasia and western Gondwana or at least of sporadic flows in both directions during the Early Cretaceous, we may opt for dispersal as an explanation. It has been assumed that there was an intercontinental bridge between Africa and Europe passing through the archipelago of which Iberia formed a part. This interpretation emerged from the idea that such a bridge existed in the Late Jurassic, explaining the presence of similar ornithopod dinosaurs in Africa and Europe. However, from the end of the Early Jurassic a period of “rift” began on the southern Iberian margin, entailing the formation of a sedimentary furrow with pelagic sedimentation in what is known as the Subbetic zone. Moreover, the differences in the observed dinosaur fauna between western Gondwana and the Iberian Peninsula in the Neocomian can be explained as the result of endemism and regional extinctions. The archipelago that formed the Iberian plate was Laurasia’s closest continental mass to Gondwana during the Neocomian, yet there was still a separation of several hundred kilometres of open ocean without islands. Such a barrier would seem difficult for dinosaurs to overcome. As such, we lack proof of communication between the two supercontinents via Iberia during the Neocomian. The situation appears to change in the Barremian-Aptian transition. Some of the taxa present in the Hauterivian-Barremian of Europe are recorded in Gondwana from the Aptian onwards. This can possibly be explained in terms of the more complete record that exists, but it cannot be ruled out that a communication was established between Gondwana and Laurasia at the end of the Barremian. For the time being, we lack geological support for this bridge in Iberia, yet it might be located in Apulia, where there is a great development of shallow-shelf carbonates with dinosaur remains from the period in question.

The potentials and limitations of dicotyledonous wood anatomy for climatic reconstructions

Paleobiology ◽  
1993 ◽  
Vol 19 (4) ◽  
pp. 487-498 ◽  
Author(s):  
Elisabeth A. Wheeler ◽  
Pieter Baas
Keyword(s):  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
Wood Anatomy ◽  
Vessel Diameter ◽  
Fossil Wood ◽  
Phylogenetic Significance ◽  
Growth Rings ◽  
Past Climate ◽  
Anatomical Features ◽  
Conflicting Information

The incidences of selected features of dicotyledonous wood that are believed to be of ecologic and/or phylogenetic significance (distinct growth rings, narrow and wide vessel diameter, high and low vessel frequencies, scalariform perforations, tangential vessel arrangement, ring porosity, and helical wall thickenings) were plotted through time (Cretaceous–Recent). There are marked differences between the Cretaceous and Tertiary in the frequency of all wood anatomical features. Incidences of features that are associated with markedly seasonal climates in extant floras do not approach modern levels until the Neogene. Correlations of wood anatomical features with ecology do not appear to have been constant through time, because in the Cretaceous different features provide conflicting information about the climate. Throughout the Tertiary the southern hemisphere/tropical and the northern hemisphere/temperate regions differed in the incidences of ecologically significant features and these differences are similar to those in the Recent flora. Possibilities for reliably using dicotyledonous wood for climatic reconstructions appear restricted to the Tertiary and Quaternary. However, at present the fossil wood record for most epochs and regions is too limited to permit detailed reconstructions of their past climate.

The morphology and relationships of Thuja polaris sp.nov. (Cupressaceae) from the early Tertiary, Ellesmere Island, Arctic Canada

1989 ◽  
Vol 67 (6) ◽  
pp. 1903-1915 ◽  
Author(s):  
E. E. McIver ◽  
J. F. Basinger
Keyword(s):  
Northern Hemisphere ◽  
Ellesmere Island ◽  
Central China ◽  
Thuja Plicata ◽  
Natural Group ◽  
Fossil Species ◽  
Early Tertiary ◽  
Seed Cone ◽  
Extant Species ◽  
Northwestern North America

Fossil foliage and seed cones of Thuja (Cupressaceae) have been discovered in early Tertiary (Paleocene) sediments of the Eureka Sound Group on Ellesmere Island, Canadian Arctic Archipelago. Vegetative remains of the fossil species, Thuja polaris sp.nov., bear alternately branched, moderately divided, flattened, and pinnatelike sprays with scale-like, decussate leaves. Seed cones are oblong, bearing 8 – 9 pairs of thin, probably leathery cone scales with distinct, reflexed umbos. Fossil cones and foliage resemble closely those of extant Thuja plicata. However, fossil seed cones have twice as many pairs of scales as do extant species of Thuja. A review of the fossil record indicates that most Thuja-like vegetative remains which have been reported from Cretaceous and Tertiary deposits in the Northern Hemisphere are best assigned to form taxa and not to extant genera. Reproductive material from four Tertiary localities can be assigned to Thuja on the basis of seed cone structure. The evolutionary history of the genus, based on fossil and extant seed cone morphology, appears to include a reduction in the number of cone scales. Extant species form a closely related, natural group and, with the exception of T. sutchuenensis, may have arisen from an ancestor similar to T. polaris. Although Thuja was widespread in the Northern Hemisphere during much of the Tertiary, the genus is now confined to northeastern and northwestern North America, and to Japan, Korea, and central China.

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