Fossil conifers

Fossil assemblages are described from the Tyers River Subgroup (late Berriasian to Hauterivian), Gippsland Basin, Victoria. The assemblages include plant macrofossils referable to 33 form-species including five new species (Isoetites abundans Tosolini & McLoughlin, Coniopteris victoriensis Nagalingum & McLoughlin, Otozamites douglasii Drinnan, Brachyphyllum tyersensis Tosolini & Nagalingum, Otwayia hermata Tosolini & McLoughlin) and three new combinations [Medwellia lacerata (Douglas) Nagalingum & McLoughlin, Rintoulia variabilis (Douglas) McLoughlin & Nagalingum, Pachydermophyllum austropapillosum (Douglas 1969) McLoughlin & Nagalingum]. Macrofossil assemblages include representatives of the Hepaticales, Isoetales, Equisetales, Filicopsida, seed-ferns, Coniferales and unionid bivalves. Co-preserved mesofossil suites include dispersed cuticle fragments, seed coats, seed megaspore membranes, microspore clusters, fern leptosporangia, charcoalified wood, resin blebs, epiphyllous fungal shields, clitellate annelid cocoons, insect exoskeleton fragments and coprolites. Sixteen lycophytic megaspore taxa were identified from the succession including six newly described species (Erlansonisporites confertus Tosolini, Favososporites brevis Tosolini, Hughesisporites australis Tosolini, Paxillitriletes rintoulensis Tosolini, Striatriletes imperfectus Tosolini, Trikonia locmaniensis Tosolini). These represent the first Neocomian megaspores formally described from Australia and their diversity and abundance indicates that lycophytes represented a significant component of the Early Cretaceous vegetation. The Tyers River Subgroup shares some taxa with the well-studied Koonwarra Fossil Bed (Aptian) flora of the Gippsland Basin but lacks several key elements (Ginkgoales, angiosperms and large-leafed araucarian conifers) and is more closely comparable to Jurassic floras of eastern Australia in its strong representation of bennettitalean, pentoxylalean and other seed-fern remains. The Tyers River Subgroup flora differs from coeval northwestern Australian floras by possession of smaller-leafed bennettites, Komlopteris and Pachydermophyllum species and by the lack of dipteridacean and gleicheniacean/lophosoriacean fern macrofossils. This intra-Australian provincialism is interpreted to be largely a function of palaeolatitude-induced climatic differences. Six major biofacies (one divisible into four sub-facies) are recognized in the Tyers River Subgroup and are attributable to three broad environmental settings within fluvial depositional tracts. Channel deposits host principally detrital plant remains derived from a broad range of riparian, upland, and reworked floodbasin communities. Silty floodbasin deposits typically host a mixture of pteridosperm-, fern- and lycophyte-dominated assemblages derived from a mosaic of herb-, shrub- and small tree-dominated communities developed mainly in perennially or seasonally wet environments. Better-drained, intervening levee, crevasse splay and neighbouring upland environments are interpreted to have hosted a conifer-dominated flora contributing to conifer-, root/rhizome-, megaspore-and clitellate-rich fossil associations. The floristic diversity, foliar morphology of selected species, strong representation of deciduous taxa and sedimentological data collectively suggest that seasonally cold conditions prevailed during the Neocomian-Aptian compared to the Albian in southeastern Australia.

The youngest Australian equisetaleans and bennettitaleans are identified within the latest Albian to early Cenomanian Winton Formation flora based on new impression fossils from the Winton district, Eromanga Basin, western Queensland. Typical Winton Formation floras are also confirmed near Isisford and Morney Plains in eastern and central Eromanga Basin. The Winton Formation flora contains over 50 macrofossil plant taxa and marks the transition from seed-fern/conifer to angiosperm dominance in the Australian floristic succession. The pattern of clade representation in Australian late Mesozoic fossil assemblages suggests a causal link between angiosperm diversification and the decline of key understorey and mid-storey plants, particularly equisetaleans, seed-ferns, ginkgophytes and some fern families, through the mid-Cretaceous.

The Budden Canyon Formation is a Cretaceous unit spanning the Valanginian–Turonian interval in northern California. This marine
unit includes plant-fossiliferous near-shore sequences, with richest plant fossil occurrences in the Hauterivian–Aptian. The Lower Chickabally
Member (Barremian–early Aptian, ca. 125 Ma) hosts a rich flora preserved anatomically in carbonate concretions, near the town of Ono. The
material is dominated by conifers: wood, foliage, cones and dispersed seeds. We characterize the anatomy of a coniferous trunk. The wood
exhibits axial and radial resin canals with thick-walled epithelial cells, distinct growth rings, and conspicuous early to late wood transition.
Axial tracheids bear radial uniseriate and opposite biseriate pitting. Rays are uniseriate with biseriate portions, with scarce ray tracheids and
taxodioid cross-field pitting. Traumatic resin canals form extensive tangential bands. The axial and radial resin canals indicate pinaceous
affinities for the Ono wood, but several characters make it different from most extant Pinaceae. The specimen is most similar to Picea Dietrich,
from which it differs in cross-field pitting. Among fossil Mesozoic genera, the Ono wood is similar to Palaeopiceoxylon Kräusel and Protocedroxylon
Gothan, and to the Pinuxylon-Laricioxylon-Piceoxylon group, but is not entirely consistent with any of these genera. Pinaceous affinity
of the Ono wood is consistent with presence in the Budden Canyon Formation of several types of pinaceous foliage and ovulate cones that
are, however, not assignable to any extant genus in the family. Together, these indicate the presence in the unit of stem-group Pinaceae
that await reconstruction as whole plants

This work presents a new age framework for the main Bashkirian glacio-eustatic transgression in Argentina, including the first absolute age for the Jejenes Formation, San Juan Province, based on radiometric dating of a crystal-rich tuff, supported by palynological and palaeofloristic studies, and presented within a revised palaeogeographic setting. The Jejenes Formation represents the glacial to postglacial fill of the Quebrada Grande palaeofjord carved in the Eastern Precordillera. The succession has been subdivided into five stages, the youngest of which suggests a previously unrecognised glacial event for this locality. Six productive levels for palynology were found within proglacial strata, and in the base and top of the succeeding interglacial stage. Palynoassemblages are characterized by poorly preserved trilete spores and monosaccate pollen grains along with a large amount of terrestrial phytoclasts. Main species indicating the Raistrickia densa-Convolutispora muriornata SubZone (DMa SZ) are Vallatisporites ciliaris, Cristatisporites rollerii, C. stellatus, C. chacoparanensis, C. inconstans and monosaccates such as Circumplicatipollis plicatus. This DMa SZ is estimated as Serpukhovian/Bashkirian and characterizes the glacial-related Guandacol Formation and equivalents units of the western Paganzo Basin. A tuffaceous level in the proglacial unit, bearing platyspermic seeds, plant remains and palynomorphs, yielded first-cycle volcanic zircons that were analysed by SHRIMP. An absolute age of 321.3 ± 5.3 Ma confirms a Bashkirian age for the main postglacial transgression in the Paganzo Basin, and offers a novel calibration for the palynoassemblages of DMa SZ that occurs elsewhere in Western Argentina.

Wood boring represents a common feeding and survival strategy in several lineages of beetles. The larvae of wood-boring beetles hatch and excavate tunnels in wood during their development. The origin and evolutionary history of this life habit, however, remain poorly understood to date, as the fossil record is scarce. We present new silicified conifer wood specimens containing complex borings from the lowermost Permian Manebach Formation of the Thuringian Forest Basin in central Germany and the lower Permian Donnersberg Formation of the Saar-Nahe Basin in southwestern Germany. Additionally, this distinctive type of wood boring is recorded from the Carboniferous/Permian of the Czech Republic, Poland and China. For these borings, the new fodinichnion or agrichnion Pectichnus multicylindricus igen. et isp. nov. is established. It is character-ised by several parallel cylindrical tunnels in a longitudinal arrangement, branching from a tangential primary tunnel oriented perpendicularly. The borings contain frass as coprolites made up of undigested wood cells. The conifer trees responded to the borings with callus production that subsequently filled or enclosed the tunnels. This is the earliest record of this specific life habit of ancient insects. The novel wood-boring strategy required structural modification and physiological adaptation; it probably emerged when insect diversity expanded considerably as terrestrial environments changed dramatically.

We describe the conifer genus Manifera (Majonicaceae, voltzian Voltziales) from the Lower Pease River flora (Early Permian, north central Texas) on the basis of dispersed ovuliferous dwarf shoots and seeds and compare it with coeval and Late Permian taxa. Manifera talaris gen. et sp. nov. is exceptional for two reasons. First, it is the earliest known conifer with winged seeds adapted for autorotating wind dispersal; second, its seeds had variable wing configurations. The ovuliferous dwarf shoots of M. talaris were stalked and bilaterally symmetrical and were composed of five partially fused sporophylls and sterile scales. The sporophylls were in median and lateral positions, and the sterile scales were in intermediate positions. The seeds bore two integument-derived wings on the chalazal end of the seed, with the secondary wing ranging in size from rudimentary to a small stub to almost equal to that of the primary wing. Single-winged seeds are the most common morphology among extant anemochorous conifer seeds. When falling, such seeds autorotate about their center of mass, which significantly slows down their descent and increases the probability of longer distance dispersal. The discovery of M. talaris seeds with these morphological traits shows that this mechanism of wind dispersal had already evolved in conifers by the Early Permian.

Since it first opened in the early 1930s, the Dinmore Claypit at Ipswich, Queensland, has been an important research and teaching destination for palaeontologists, educators and students. Today, nearly 80 years later, the relevance of this unique resource remains undiminished.

Junior homonyms of fossil species,
Abies protofirma Tanai 1961 (non Zaklinskaja
1957) and Abies minor Ananova 1974 (non
Velenovský 1885), are replaced with new
names respectively, A. praefirma Doweld and
Abiespollenites ananovae Doweld. The validity
of the fossil species A. minor Velenovský 1885
is no more affected by the devalidated species
name A. minor Gilibert 1792, which is in the
works now suppressed by The International Code
of Nomenclature for Algae, Fungi, and Plants
(Opera utique oppressa).