Podozamites

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Podozamites
Temporal range: Middle Triassic–Late Cretaceous
HKU Xiang Gang Da Xue Stephen Hui Geological Museum Xu Shi Fen Di Zhi Bo Wu Guan Mesozoic Zhong Sheng Dai Dinosaur world plants rocks Oct 2016 Lnv 06.jpg
Fossil Podozamites from China
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Gymnospermae
Division: Pinophyta
Class: Pinopsida
Genus: Podozamites
Braun 1843

Podozamites is an extinct genus of fossil conifer leaves. In its broader sense, it has been used as a morphogenus (form taxon) to refer to any broad leaved multi-veined conifer leaves. Modern broad-leaved conifers with a similar form include Agathis in the family Araucariaceae and Nageia in Podocarpaceae, with some Podozamitessensu lato probably belonging to the same families. [1]

Contents

In a more narrow sense, Podozamites has been used to refer to the leaves of a probably monophyletic group of deciduous broad leafed voltzialean conifers which lived in the Northern Hemisphere, particularly East Asia and Siberia, during the Late Triassic to early Late Cretaceous, where it formed part of wet coal swamp communities. [1]

Description

Reconstruction of Podozamities harrisii with the associated cones of Krassilovia mongolica from the Early Cretaceous of Mongolia. Art by Pollyanna von Knorring Krassilovia mongolica and Podozamites harrisii.png
Reconstruction of Podozamities harrisii with the associated cones of Krassilovia mongolica from the Early Cretaceous of Mongolia. Art by Pollyanna von Knorring
Cycadocarpidium erdmanni cone & Podozamites schenkii leaves from the Late Triassic of Iran Cycadocarpidium erdmanni & Podozamites schenkii.png
Cycadocarpidium erdmanni cone & Podozamites schenkii leaves from the Late Triassic of Iran

In the right conditions, Podozamites leaves sensu stricto preserve delicate cuticle and insect damage, and are thought to have been regularly shed. They are associated with conifer cones of the genera Swedenborgia, Cycadocarpidium, and Krassilovia . [2]

Podozamites leaves are strap-shaped or oblong, with smoothly parallel sides and dense longitudinal veins. They attach to a slender branch in a helical pattern, but twist into a distichous orientation (lying in a single plane along the branch). Both the upper (adaxial) and lower (abaxial) surfaces of the leaf have cells arranged into longitudinal bands. Some bands on the abaxial surface host broad stomata which are paracytic (with a subsidiary cell lateral to and paralleling each guard cell in a stoma). This is similar to Gnetales and especially bennettitaleans, suggesting that they may be related to these groups. [3]

The Krassilovia cone is roughly spherical and consists of densley packed interlocking overlapping bract-scale complexes surrounding a central axis. The cone is thought to have disintegrated at maturity to release the winged seeds. By contrast, the Swedenborgia and Cycadocarpidium cones are elongate and are only loosely packed. [2]

Evolutionary history

Podozamites sensu stricto has been suggested to be closely related to Telemachus/Heidiphyllum (seed cone/leaves respectively), a broad-leaved conifer known from the Triassic of Gondwana. [2] Podozamites sensu stricto first became widespread at mid-latitudes during the Late Triassic. During the Early Jurassic in East Asia, it formed almost monospecific assemblages where it was the dominant plant. Over the course of the Jurassic, the distribution shifted northwards in response to the drying of the lower latitudes, becoming restricted to between 60 and 30 degrees north by the Early Cretaceous. Podozamites senus stricto would become extinct during the Turonian stage of the Late Cretaceous, coincident with the arrival of flowering plants into the Siberian region. [1]

Species

A number of species within the genus were listed by Fossilworks, as of May 2021: Podozamites agardhianus, Podozamites distans, Podozamites lanceolatus, Podozamites longifolius, Podozamites mucronatus, Podozamites pinnatus and Podozamites schenki. [4] Agathis jurassica , initially identified as Podozamites lanceolatus, has also been placed in this genus. [5] Podozamites harrissii from the Early Cretaceous of Mongolia is associated with Krassilovia mongolica, while Podozamites schenkii is associated with the Triassic-Jurassic Swedenborgia cryptomerioides and Triassic Cycadocarpidium erdmanni. [2] It has been noted that extant Agathis (Araucariaceae) and Nageia (Podocarpaceae) qualify as members of Podozamites under its morphogenus sense. [1]

Related Research Articles

Ginkgoopsida is a proposed class of gymnosperms defined by Sergei V. Meyen in 1984 to encompass Ginkgoales alongside a number of extinct seed plant groups, which he considered to be closely related based on similarities of morphology of pollen, seeds, cuticles, short shoots and leaves. The validity of this group as a whole has been considered questionable by other authors, who consider that it is unlikely to be monophyletic. Other authors have used the class as a monotypic grouping, including only Ginkgoales. Some authors have used the clade Ginkgophyta to encompass both Ginkgoales and Czekanowskiales/Leptostrobales, which are suggested to be closely related groups.

<span class="mw-page-title-main">Araucariaceae</span> Family of plants

Araucariaceae – also known as araucarians – is a family of coniferous trees, with three living genera, Araucaria, Agathis, and Wollemia. While the family was distributed globally during the Jurassic and Cretaceous periods, they are now largely confined to the Southern Hemisphere, except for a few species of Agathis in Southeast Asia.

<span class="mw-page-title-main">Pinaceae</span> Family of conifers

The Pinaceae, or pine family, are conifer trees or shrubs, including many of the well-known conifers of commercial importance such as cedars, firs, hemlocks, piñons, larches, pines and spruces. The family is included in the order Pinales, formerly known as Coniferales. Pinaceae are supported as monophyletic by their protein-type sieve cell plastids, pattern of proembryogeny, and lack of bioflavonoids. They are the largest extant conifer family in species diversity, with between 220 and 250 species in 11 genera, and the second-largest in geographical range, found in most of the Northern Hemisphere, with the majority of the species in temperate climates, but ranging from subarctic to tropical. The family often forms the dominant component of boreal, coastal, and montane forests. One species, Pinus merkusii, grows just south of the equator in Southeast Asia. Major centres of diversity are found in the mountains of southwest China, Mexico, central Japan, and California.

<i>Araucaria</i> Genus of evergreen conifers in the family Araucariaceae

Araucaria is a genus of evergreen coniferous trees in the family Araucariaceae. While today they are largely confined to the Southern Hemisphere, during the Jurassic and Cretaceous they were distributed globally. There are 20 extant species in New Caledonia, Norfolk Island, eastern Australia, New Guinea, Argentina, Brazil and Chile.

<i>Agathis</i> Genus of conifers in the kauri family Araucariaceae

Agathis, commonly known as kauri or dammara, is a genus of evergreen coniferous trees, native to Australasia and Southeast Asia. It is one of three extant genera in the family Araucariaceae, alongside Wollemia and Araucaria. Its leaves are much broader than most conifers. Kauri gum is commercially harvested from New Zealand kauri.

<span class="mw-page-title-main">Podocarpaceae</span> Family of conifers in the family Podocarpaceae

Podocarpaceae is a large family of mainly Southern Hemisphere conifers, known in English as podocarps, comprising about 156 species of evergreen trees and shrubs. It contains 19 genera if Phyllocladus is included and Manoao and Sundacarpus are recognized.

<i>Podocarpus</i> Genus of conifers in the family Podocarpaceae

Podocarpus is a genus of conifers, the most numerous and widely distributed of the podocarp family, the Podocarpaceae. The name comes from Greek πούς + καρπός. Podocarpus species are evergreen shrubs or trees, usually from 1 to 25 m tall, known to reach 40 m (130 ft) at times. The cones have two to five fused cone scales, which form a fleshy, berry-like, brightly coloured receptacle at maturity. The fleshy cones attract birds, which then eat the cones and disperse the seeds in their droppings. About 97 to 107 species are placed in the genus depending on the circumscription of the species.

<i>Nageia</i> Genus of conifers in the family Podocarpaceae

Nageia is a genus of conifers belonging to the podocarp family Podocarpaceae. Nageia includes evergreen shrubs and trees, from one to 54 meters in height. A 2009 treatment of the genus recognized five species. Some authors consider Nageia formosensis to be a separate species from Nageia nagi, thus recognizing six species. The podocarp genera have been reshuffled by various botanists. Most recently, several species formerly classed as Nageia were moved to the new genus Retrophyllum, while Nageia falcata and Nageia mannii were moved to the new genus Afrocarpus.

Palissya is an extinct form genus of female (ovule-bearing) conifer cones, known from the Late Triassic (Rhaetian) to the Early Cretaceous (Aptian). The cone of Palissya is noted for its unusual catkin-like construction: Slender bracts are rigidly attached in a helical pattern around a tall woody core. The adaxial (upper) surface of each bract bears two parallel rows of ovules which are encased in cup-like structures formed by scales. The seeds are thin-walled and were likely only viable for a short period of time, meaning that they were probably adapted to wind dispersal.

<i>Retrophyllum</i> Genus of conifers

Retrophyllum is a genus of conifers in the family Podocarpaceae. It contains five generally recognized extant species with a disjunct distribution in the Southern Hemisphere, found in Papuasia and also in South America. Retrophyllum are evergreen trees typically occurring in tropical rainforests and cloud forests.

<i>Amentotaxus</i> Genus of conifers

Amentotaxus is a genus of conifers (catkin-yews) comprising five species, treated in either the Cephalotaxaceae, or in the Taxaceae when that family is considered in a broad sense. The genus is endemic to subtropical Southeast Asia, from Taiwan west across southern China to Assam in the eastern Himalaya, and south to Vietnam. The species are evergreen shrubs and small trees reaching 2–15 m tall.

<span class="mw-page-title-main">Cheirolepidiaceae</span> Extinct family of conifers

Cheirolepidiaceae is an extinct family of conifers. They first appeared in the Triassic, and were widespread during most of the Mesozoic era. They are united by the possession of a distinctive pollen type assigned to the form genus Classopollis. The name Frenelopsidaceae or "frenelopsids" has been used for a group of Cheirolepidiaceae with jointed stems, thick internode cuticles, sheathing leaf bases and reduced free leaf tips. The leaf morphology has been noted as being similar to that of halophyte Salicornia. Several members of the family appear to have been adapted for semi-arid and coastal settings, with a high tolerance of saline conditions. Cheirolepidiaceae disappeared from most regions of the world during the Cenomanian-Turonian stages of the Late Cretaceous, but reappeared in South America during the Maastrichtian, the final stage of the Cretaceous, increasing in abundance after the K-Pg extinction and being a prominent part of the regional flora during the Paleocene, before going extinct.

<span class="mw-page-title-main">Voltziales</span> Extinct order of conifers

Voltziales is an extinct order of conifers. The group contains the ancestral lineages from which modern conifer groups emerged. Voltzialean conifers are divided into two informal groups, the primitive "walchian conifers" like Walchia, where the ovuliferous cone is composed of radial shoots and the more advanced "voltzian voltziales", also known as "transitional conifers" where the cone is composed of fertile scales with sessile seeds, like those of modern conifers. Walchian conifers generally grew as small trees. The earliest walchian conifers are known from the Middle Pennsylvanian (Moscovian). The youngest walchian conifers are known from the Late Permian. The earliest "voltzian voltziales" are known from the late Early Permian (Kungurian). Modern conifer lineages emerged from voltzialean ancestors from the Late Permian to Jurassic. Voltzialean conifers outside modern groups such as Krassilovia/Podozamites survived into the Cretaceous, before becoming extinct. The genus Voltzia was named in honour of the French geologist Philippe Louis Voltz.

<i>Umkomasia</i> Extinct genus of seed ferns

Umkomasia is a genus of seed bearing organs produced by corystosperm seed ferns, first based on fossils collected by Hamshaw Thomas from the Burnera Waterfall locality near the Umkomaas River of South Africa. He recognized on the basis of cuticular similarities that the same plant produced pollen organs Pteruchus and the leaves Dicroidium. Various other corystosperm seed bearing organs from the Jurassic and Cretaceous have been assigned to this genus, but recently have been given distinct genera, with Umkomasia being restricted to the Triassic.

<span class="mw-page-title-main">Corystospermaceae</span> Extinct family of seed ferns

Corystosperms are a group of extinct seed plants belonging to the family Corystospermaceae assigned to the order Corystospermales or Umkomasiales. They were first described based on fossils collected by Hamshaw Thomas from the Burnera Waterfall locality near the Umkomaas River of South Africa. Corystosperms are typified by a group of plants that bore forked Dicroidium leaves, Umkomasia cupulate ovulate structures and Pteruchus pollen organs, which grew as trees that were widespread over Gondwana during the Middle and Late Triassic. Other fossil Mesozoic seed plants with similar leaf and/or reproductive structures have also sometimes been included within the "corystosperm" concept sensu lato, such as the "doyleoids" from the Early Cretaceous of North America and Asia. A potential corystosperm sensu lato, the leaf genus Komlopteris, is known from the Eocene of Tasmania, around 53-50 million years old, over 10 million years after the Cretaceous–Paleogene extinction event.

This article records new taxa of plants that are scheduled to be described during the year 2017, as well as other significant discoveries and events related to paleobotany that are scheduled to occur in the year 2017.

This article records new taxa of plants that were described during the year 2014, as well as other significant discoveries and events related to paleobotany that occurred in the year 2014.

"<i>Agathis</i>" <i>jurassica</i> Extinct species of conifer

"Agathis" jurassica is an extinct coniferous tree found in the Talbragar Fish Beds of New South Wales. The beds were discovered in 1889 near the Farrs Hills in the Talbragar River valley. Specimens from the area were briefly examined by Australian palaeontologists upon discovery and published by R. Etheridge Jr. later that year. The initial classification identified Agathis jurassica as Podozamites lanceolatus. This name was upheld through further inspections by Walkom in 1921, but the species was reclassified as Agathis jurassica in 1981 by Mary White. In 1999, placement in Agathis was doubted, and the species has been referred to as Podozamites jurassica. The species is found predominantly in the Southern Hemisphere with marginal expanses into the Northern Hemisphere.

<i>Umaltolepis</i> Extinct genus of plants

Umaltolepis is an extinct genus of seed plant, known from the Early Jurassic to Early Cretaceous of Asia. Within the form classification system used within paleobotany, it refers to the seed-bearing reproductive structures, which grew on woody plants with strap-shaped Ginkgo-like leaves assigned to the genus Pseudotorellia.

Araucarioides is an extinct genus of conifer belonging to the family Araucariaceae. The type species Araucarioides linearis is known from the Early Eocene of Tasmania, with fossils including isolated leaves, parts of the conifer cone, as well as possible seeds, associated with Dilwynites tuberculatus pollen. Another species only known from leaves, Araucarioides falcata is known from the Late Cretaceous (Campanian) of New Zealand. Phylogenetic analysis suggests that Araucarioides linearis is closely related to both Agathis and Wollemia rather than to Araucaria.

References

  1. 1 2 3 4 Pole, Mike; Wang, Yongdong; Bugdaeva, Eugenia V.; Dong, Chong; Tian, Ning; Li, Liqin; Zhou, Ning (December 2016). "The rise and demise of Podozamites in east Asia—An extinct conifer life style". Palaeogeography, Palaeoclimatology, Palaeoecology. 464: 97–109. Bibcode:2016PPP...464...97P. doi:10.1016/j.palaeo.2016.02.037.
  2. 1 2 3 4 Herrera, Fabiany; Shi, Gongle; Mays, Chris; Ichinnorov, Niiden; Takahashi, Masamichi; Bevitt, Joseph J.; Herendeen, Patrick S.; Crane, Peter R. (2020-01-15). Peppe, Daniel (ed.). "Reconstructing Krassilovia mongolica supports recognition of a new and unusual group of Mesozoic conifers". PLOS ONE. 15 (1): e0226779. Bibcode:2020PLoSO..1526779H. doi: 10.1371/journal.pone.0226779 . ISSN   1932-6203. PMC   6961850 . PMID   31940374.
  3. Shi, Gongle; Herrera, Fabiany; Herendeen, Patrick S.; Leslie, Andrew B.; Ichinnorov, Niiden; Takahashi, Masamichi; Crane, Peter R. (2018-01-26). "Leaves of Podozamites and Pseudotorellia from the Early Cretaceous of Mongolia: stomatal patterns and implications for relationships". Journal of Systematic Palaeontology. 16 (2): 111–137. Bibcode:2018JSPal..16..111S. doi:10.1080/14772019.2016.1274343. ISSN   1477-2019. S2CID   90523531.
  4. "†Podozamites Braun 1843 (conifer)". Fossilworks . Retrieved 2021-05-17from the Paleobiology Database.{{cite web}}: CS1 maint: postscript (link)
  5. Frese, M.; Gloy, G.; Oberprieler, R.G. & Gore, D.B. (2017). "Imaging of Jurassic fossils from the Talbragar Fish Bed using fluorescence, photoluminescence, and elemental and mineralogical mapping". PLOS ONE. 12 (6): e0179029. Bibcode:2017PLoSO..1279029F. doi: 10.1371/journal.pone.0179029 . PMC   5459505 . PMID   28582427.