The conifer genus Palissya is reviewed giving special attention to assessing the reliability of Gondwanan material referred to this genus. The collection localities of
The plant fossil genera Umkomasia Thomas 1933 and Pteruchus Thomas 1933 emend. Townrow 1962 are known chiefly from the Middle and Upper Triassic of Gondwana. The structure of these fructifications has been conjectural, some being identified as pinnate, others as helically arranged. Specimens from the Ladinian-lower Norian of Queensland (northeastern Australia) show that the female and male fructifications - U. geminata (Shirley 1898) Rigby in Playford et al. 1982 emend. nov. and P. dubius Thomas 1933 emend. Townrow 1962, respectively - have a bipinnate structure. Those fructifications and the bipinnate leaf, Dicroidium feistmantelii (Johnston 1894) Gothan 1912, probably all belonged to the same parent plant. It was first suggested by John Townrow in 1962 that the sporangial heads of P. dubius have a pinnate structure; this character is confirmed herein. Pteruchus is recorded for the first time from the Carnian Tarong Basin, Queensland.The holotype of Stachyopitys simmondsii Shirley 1898 is shown to be ovuliferous. The species is recombined as Umkomasia simmondsii (Shirley 1898) comb. et emend. nov. Genuine male fructifications, previously identified as S. simmondsii, and later as Pteruchus simmondsii (Shirley 1898) Jones and de Jersey 1947, are assigned to P. minor Thomas 1933. That species comprises the smallest fructifications of the genus. Townrovia polaris Bomfleur et al. 2011 and Stachyopitys lacrisporangia Anderson & Anderson 2003 are identified as junior synonyms to P. minor. The diagnosis of Townrovia Retallack 1981 is inaccurate and the genus is insufficiently distinguished from Pteruchus.
ABSTRACT. Umkomasiaceans are the most commonly recorded components of Gondwanan Triassic floras but they are not represented subsequently in that region. Their diversity appears to have substantially declined prior to the Rhaetian. Lower and Middle Jurassic floras in Australia and elsewhere in Gondwana are strikingly different from those of the Triassic, comprising ferns, lycopods, conifers, cycads, and bennettitaleans. The fern Cladophlebis Brongniart 1849 emend. Seward 1894 dominated coal-forming paludal environments during the Middle Jurassic in Queensland and it is one of the most commonly preserved plants in the Eastern Gondwanan Jurassic. Ginkgoaleans were present in Eastern Gondwana until near the end-Triassic but were absent below ca 60°S palaeolatitude during the Early and Middle Jurassic.The type specimen of Dicroidium superbum (Shirley 1898) Townrow 1957 emend. nov. has been inaccurately represented in the published record. Consequently, many specimens belonging to the species have been incorrectly assigned to other umkomasiacean species. Misidentifications and considerably enlarged circumscriptions of some species have resulted in an erroneous and simplistic morpho-continuum concept supposedly linking umkomasiacean fronds. Several commonly occurring umkomasiacean species are re-assessed with particular attention to their type specimens, two of which are accurately figured here for the first time. This re-assessment, together with evidence from allied fructifications and wood, supports the view that umkomasiacean fronds belong to several genera. Most umkomasiacean lineages probably terminated prior to the Rhaetian; however, Zuberia Frenguelli 1943 emend. Artabe 1990 persisted to near the close of the Triassic.
The plant megafossil genus Linguifolium Arber 1917 is chiefly known from the Middle and Upper Triassic of Gondwana. The range of Linguifolium extended beyond Gondwana by the Late Triassic, persisting there through the earliest Jurassic (Hettangian). The parent plants probably grew in a well-watered, canopied environment. Diagnoses of the genus and four of its species - Linguifolium tenison-woodsii (Shirley 1898) Retallack 1980, L. waitakiense Bell in Bell et al. 1956, L. parvum Holmes & Anderson in Holmes et al. 2010, and L. steinmannii (Solms-Laubach 1899) Arber 1917 - are emended with particular reference to venation and leaf morphology; consequently, the stratigraphic ranges of the species have been more precisely defined. Coalescent venation has previously been reported in some species of Linguifolium and is identified in new material described herein. Although the vast majority of specimens assigned to the genus are from the Upper Triassic, none shows coalescent venation. This character is entirely restricted to the Middle Triassic, in particular to two species: L. waitakiense and L. parvum. Linguifolium tenison-woodsii is restricted to the Carnian-lowermost Norian of Australia and South Africa and is recorded here for the first time from the Tarong Basin (upper Carnian), Queensland. Confusion regarding assignment of specimens to this species from the Middle Jurassic of Queensland is resolved.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.