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The morphology of the adaxial structures of cones belonging to Palissya Endlicher 1847 emend. nov. are reinterpreted based on exquisitely preserved permineralised material from the Lower Cretaceous of Queensland. Although the material was not found in situ, it likely derives from the Orallo Formation, which is Valanginian in age. The cones have dual vascular bundles in each bract/scale complex, and the different tissue types in the bract and ovule/scale complex support interpretation of the cone as a compound structure. Since the early twentieth century it has been widely accepted that each ovule is surrounded by a cup-shaped structure, but the detailed morphology of the “cup” has hitherto been unclear. These new three-dimensionally preserved specimens with in situ ovules are described as Palissya tillackiorum sp. nov. This study demonstrates that the “cup” is formed from a pair of thin scales that subtend but are not fused to each ovule; each pair of scales comprises a thicker outer and thinner inner scale. The organographic relationships among ovules and scales in Palissya show a high degree of synorganisation. The adaxial surface of the bract/scale complex has 2–6 pairs of erect (orthotropous) ovules. The ovule/scale units are arranged symmetrically in two parallel rows on either side of the midline of the bract/scale. Individual ovule/scale units are comparable to those seen in extant Podocarpaceae and Taxaceae. The ovules are thin-walled and are interpreted to have a single integument and a non-thickened (non-lignified) micropyle. These new insights allow reinterpretation of material previously referred to Palissya. A new species is described from Yorkshire, England, as P. harrisii C.R. Hill ex Pattemore & Rozefelds sp. nov. All species based on well preserved cones are reconsidered herein: P. sphenolepis (Braun 1843) Nathorst 1908 emend. Florin 1958, P. elegans Parris, Drinnan & Cantrill 1995 emend. nov., P. bartrumii Edwards 1934 emend. nov., P. antarctica Cantrill 2000 and P. hunanensis Wang 2012. Palissya ovalis Parris et al. 1995 differs structurally from Palissya and is transferred to Knezourocarpon Pattemore 2000 emend. nov. Representatives of this genus may superficially resemble those of Palissya in compressions and impressions, and their congeneric status has been previously suggested; hence its inclusion in this study. Knezourocarpon has adaxial processes that are positioned in two parallel rows but it lacks ovules and paired lateral scales that formed a cup-shape, and its processes attach directly to a central vascular trace. The improved understanding of Palissya’s morphology allows for definite separation of these genera, although the higher-order affiliation of Knezourocarpon remains unclear.

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.

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.

The conifer genus Palissya is reviewed giving special attention to assessing the reliability of Gondwanan material referred to this genus. The collection localities of Australasian specimens are mapped on palaeogeographic reconstructions of Eastern Gondwana at relevant times between 179 Ma and 119 Ma. Australasian and other Gondwanan material previously referred to Palissya is considered to differ substantially from the generic diagnosis. Specimens from the Toarcian of Australasia are shown to be allied to Knezourocarpon; this genus is only known from the Toarcian of eastern Australia. Middle Jurassic–Lower Cretaceous Australasian specimens previously referred to Palissya are likely allied to the Knezourocarponaceae fam. nov. The higher taxonomic affinity of this family is unknown but broadly, its structure is suggestive of ginkgoalean or pteridospermous affiliation. Southern hemisphere specimens were probably catkin-like and megascopically very different from the northern hemisphere Palissya and the two groups are unlikely to be closely related. Consequently, genuine Palissya cones and foliage appear to be restricted to the Rhaetian–Lower Jurassic of the northern hemisphere.