STRUCTURE AND AFFINITIES OF PROTOSTIGMARIA EGGERTIANA

Investigation of new, more or less complete specimens of Protostigmaria eggertiana reveals that it is a large, multilobed rooting structure produced at the base of a small arborescent lycopod. The trunk bears scars marking the point of attachment of leaves, and can be compared to the stem of Lepidodendropsis. In the largest specimens the root-bearing base is divided into about 13 lobes. In smaller, presumably younger specimens, fewer lobes are present. The roots are arranged on the lobes in series and orthostichies comparable to those of Isoetes. New observations on five- and six-lobed Isoetes plants reveal a closer correspondence between Protostigmaria and Isoetes than previously recognized; and support suspected homologies among many fossil and extant lycopsid rooting structures.     

贵州寒武系第二统杷榔组有壳变形虫的新发现*

有壳变形虫(testate amoebae)的演化历史最早可追溯至新元古代早期, 以该时期北美、华北、挪威以及澳洲等多个地区浅海相碳酸盐岩、页岩中发现的瓶状微体化石(vase-shaped microfossils)为标志。此前认为, 显生宙的有壳变形虫最早出现在早泥盆世。长期以来, 早古生代的地层中未发现这类原生生物的明确化石证据。本研究通过对岩石样品进行常规孢粉酸泡分析处理和切磨岩石薄片, 获取原位保存的化石标本的技术方法, 从贵州东部剑河县交榜剖面出露的寒武系杷榔组(第2统第4阶)中获得数枚有壳变形虫(testate amoebae)化石标本。基于标本的显微形态特征, 并结合激光拉曼光谱等研究, 对原先记述为疑源类的Plagasphaera balangensis和P. sp. A两形态种进行重新认识和描述。由于它们在结构和形态上与一些现生的鳞壳虫目(Euglyphida)有壳变形虫极为相似, 因此将先前定为疑源类的Plagasphaera balangensis和P. sp. A两形态属、种名, 分别修订为Palaeoassulina balangensis gen. et sp. nov.和?Palaeoassulina sp. A。该发现不仅将显生宙有壳变形虫的原有化石记录从晚古生代泥盆纪向前延伸至寒武纪早期, 还为调查研究有壳变形虫的系统演化提供关键的生物化石证据。     

An anatomically preserved lycopsid from the Upper Devonian of South China

An anatomically preserved lycopsid, Lobodendron fanwanensegen. et sp. nov. Liu, Wang, Xue & Meng, is described from the Upper Devonian (Famennian) Wutong Formation of Changxing County, Zhejiang Province, China. The fossil plant bears slender, dichotomously branched axes. The vascular strand consists of solid terete primary xylem and lobed secondary xylem, which implies the result from the activity of possibly discontinuous cambium. The new plant has character combinations that do not conform to any branches in the canopy of the tree-lycopsids known previously, but resemble those of the basal part of some pseudoherbaceous lycopsids. This new plant may exemplify a Late Devonian lycopsid with a pseudoherbaceous growth habit.     

COMPARATIVE PALEOBIOCHEMISTRY OF SOME FOSSIL AND EXTANT FAGACEAE

A Fagus-like leaf fossil (cuticular compression) with an attached fruit, differing from any known Fagus species (fossil or extant) or other fagoid taxa, has been discovered from the Miocene Clarkia Lake deposits of northern Idaho. Because of its unusual morphology (especially the fruit) the fossil taxon has been described as a new genus and species, Pseudofagus idahoensis Smiley and Huggins. The successful previous use of paleobiochemistry in studies of fossil taxa from the Miocene Succor Creek Flora of Oregon suggested that chemical data might help clarify the taxonomic affinities of Pseudofagus. Indeed, examination of the chemistry of the fossil, Pseudofagus idahoensis, and comparison with extant Fagus species and related fagoid genera indicate that: 1) based on steroid chemistry, Pseudofagus idahonesis does belong in the Fagaceae; 2) like all extant species of Fagus, the fossil lacks the tannin component, ellagic acid, which separates it from other extant fagoid genera, and 3) its simple flavonoid pigment profile places it closest to the extant North American Fagus grandifolia or the European/Eurasian Fagus sylvatica. However, the exclusive presence of an isorhamnetin (3'-methoxyquercetin) 3-0-glycoside, onocerane, and 5α-cholestane imparts a species-specific chemical character to Pseudofagus idahoensis, which also sets it apart from extant species of Fagus. While the chemistry does not decide the taxonomic level to be accorded to the fossil, it certainly supports, along with morphology and anatomy, the distinctness of Pseudofagus and its proposed relationships within the Fagaceae.     

Fossil flowers and fruits of the Actinidiaceae from the Campanian (Late Cretaceous) of Georgia

A new genus and species of Actinidiaceae (Parasaurauia allonensis gen. et sp. nov.) are established for fossil flowers and fruits from the early Campanian (Late Cretaceous) Buffalo Creek Member of the Gaillard Formation in central Georgia, USA. The fossil flowers, which are exquisitely preserved as charcoal, have five imbricate, quincuncially arranged sepals and petals. The androecium consists of ten stamens with anthers that are deeply sagittate proximally. The gynoecium is tricarpellate, syncarpous, and has three free styles that emerge from an apical depression in the ovary. The fruit is trilocular and contains numerous ovules on intruded axile placentae. The structure of mature fruits is unknown. Comparisons with extant taxa clearly demonstrate that the affinities of Parasaurauia allonensis are with the Ericales, and particularly with the Actinidiaceae, which have been placed among the Ericales in recent cladistic analyses. Because Parasaurauia allonensis is not identical to any one genus of Actinidiaceae, or other member of the Ericales, phylogenetic relationships of the fossil were evaluated through a cladistic analysis using morphological and anatomical characters. Results of this analysis place Parasaurauia allonensis within the Actinidiaceae as sister to the extant genera Saurauia and Actinidia. Parasaurauia allonensis differs from extant Saurauia only in having ten rather than numerous stamens.     

CHLORANTHUS-LIKE STAMENS FROM THE UPPER CRETACEOUS OF NEW JERSEY

Fossil angiospermous stamens with in situ pollen from the Turonian (ca. 90 million years before present, Late Cretaceous) of New Jersey are described and assigned to the Chloranthaceae. The fossil stamens, which are three-parted and bear two bisporangiate thecae on the central lobe and one bisporangiate theca on each lateral lobe, are indistinguishable from stamens of several extant species of Chloranthus. The pollen is spheroidal, 13–18 μm in diameter, with a reticulate exine and apparently elongate/elliptical apertures. The pollen is similar to that in extant Chloranthus in grain size, shape, exine sculpture, and aperture structure. Like pollen of some extant species of Chloranthus, aperture number in the fossil pollen appears to be variable. Because fossil pistillate chloranthoid reproductive structures have not been found at this locality it is unknown whether the fossil stamens described here were borne on the side of the ovary, as in extant Chloranthus, or in another arrangement. The three-parted stamen of Chloranthus is unique in angiosperms and there has been considerable debate concerning the origin and evolutionary significance of the structure. Uncertainty as to whether the three-parted stamen represents a synapomorphy for the genus or a retained plesiomorphy in angiosperms is the primary reason why these fossil stamens are not assigned to the extant genus Chloranthus.     

A new genus and species of fossil scorpion (?Euscorpiidae) from the Early–Middle Eocene of Pesciara (Bolca,Italy)

Fossil scorpions are among the oldest terrestrial arthropods known from the fossil record. They have a worldwide distribution and a rich fossil record, especially for the Paleozoic. Fossil scorpions from Mesozoic and Cenozoic deposits are usually rare (except in amber-deposits). Here, we describe the only fossil scorpion from the Early to Middle Eocene Pesciara Lagerstätte in Italy. Eoeuscorpius ceratoi gen. et sp. nov. is probably a genus and species within the family Euscorpiidae. This may be the first fossil record of the Euscorpiidae, which are so far only known from four extant genera. Eoeuscorpius ceratoi gen. et sp. nov. was found in the “Lower Part” of the Pesciara Limestone, which is actually dated Late Ypresian stage (between 49.5 and 49.7 Ma). Besides a possible pseudoscorpion, the here-described fossil scorpion is the second arachnid species known from the Bolca Locality.     

Labyrinth morphology and the evolution of low-frequency phonoreception in elasmobranchs

Labyrinth morphology in extant elasmobranchs (neoselachians: sharks, skates and rays) and several extinct chondrichthyans ranging in age from Pliocene to Devonian is investigated using high-resolution computed tomography (CT scanning) and digital reconstitution techniques. The elasmobranch labyrinth is highly specialized toward low-frequency semi-directional sound detection (LFSDP), optimally around 100 Hz. Several features associated with LFSDP in neoselachians also occur in Mesozoic hybodonts (e.g., Egertonodus, Tribodus) and in some incertae sedis extinct sharks (Acronemus, Tristychius), but are absent in osteichthyans, extant and fossil holocephalans, and certain Paleozoic chondrichthyans (ctenacanths, symmoriiforms, Pucapampella). Thus, LFSDP is regarded as an evolutionary novelty of elasmobranchs that arose some time after their divergence from chimaeroids. The suite of characters associated with LFSDP was probably acquired progressively, some characters being more widely distributed among fossil chondrichthyans than others. LFSDP evolved only within chondrichthyans whose otico-occipital fissure became secondarily closed during ontogeny.     

ANGIOSPERM PALEOBIOCHEMISTRY OF THE SUCCOR CREEK FLORA (MIOCENE) OREGON,USA

The organic chemical profiles of fossil Acer and Quercus leaf tissues are presented and correlated with those of previously described fossil Celtis, Ulmus and Zelkova and interpreted in conjunction with referable extant genera. Intrageneric comparisons among fossil and extant taxa indicate that relatively minor phytochemical differences exist suggesting that little flavonoid and steroid evolution since post-Miocene times has occurred. Biosystematic relationships between living North American and Asian genera indicate that in some cases (Quercus, Zelkova) a greater affinity exists between living Asiatic species and elements of the Succor Creek Flora. The chemical data are proposed as an independent parameter in assessing angiosperm biogeography and proposed migration patterns of the Fagaceae and Ulmaceae. The high chemical fidelity seen between some living and fossil genera preserved in ash-fall deposits is ascribed to the reaction of membrane bound lipids with various organic acids and to subsequent rapid dehydration.     

STEM-ROOT TRANSITION OF AN UPPER PENNSYLVANIAN WOODY LYCOPSID

Anatomically preserved specimens of a woody lycopsid showing the transition from the stem to the rooting region are described from the Upper Pennsylvanian Duquesne Coal of Ohio. Specimens have exarch protosteles that are apparently medullated at distal levels and exhibit abundant secondary xylem. Cortical tissues accompanying the stems have periderm, and show leaf bases or cushions. Although features of the stems are compatible with those of the arborescent Lepidodendrales, the plants have a rounded cormose rooting region, rather than the much-branched and elongated stigmarian system usually associated with the order. Specimens of this type expand our knowledge of the diversity among Paleozoic lycopsids and document the occurrence of representatives with an Isoetes-like base in Pennsylvanian strata.     

A Total Evidence Phylogeny of the Arctoidea (Carnivora: Mammalia): Relationships Among Basal Taxa

A total evidence phylogenetic analysis was performed for 14 extant and 18 fossil caniform genera using a data matrix of 5.6 kbp of concatenated sequence data from six independent loci and 80 morphological characters from the cranium and dentition. Maximum parsimony analysis recovered a single most parsimonious cladogram (MPC). The topology of the extant taxa in the MPC agreed with previous molecular phylogenies. Phylogenetic positions for fossil taxa indicate that several taxa previously described as early members of extant families (e.g., Bathygale and Plesictis) are likely stem taxa at the base of the Arctoidea. Taxa in the “Paleomustelidae” were found to be paraphyletic, but a monophyletic Oligobuninae was recovered within this set of taxa. This clade was closely related to the extant genera Gulo and Martes, therefore, nested within the extant radiation of the family Mustelidae. This analysis provides a resolution to several discrepancies between phylogenies considering either fossil taxa or extant taxa separately, and provides a framework for incorporating fossil and extant taxa into comprehensive combined evidence analyses.     

Carboniferous Onychophora from Montceau‐les‐Mines,France, and onychophoran terrestrialization

The geological age of the onychophoran crown‐group, and when the group came onto land, have been sources of debate. Although stem‐group Onychophora have been identified from as early as the Cambrian, the sparse record of terrestrial taxa from before the Cretaceous is subject to contradictory interpretations. A Late Carboniferous species from the Mazon Creek biota of the USA, Helenodora inopinata, originally interpreted as a crown‐group onychophoran, has recently been allied to early Cambrian stem‐group taxa. Here we describe a fossil species from the Late Carboniferous Montceau‐les‐Mines Lagerstätte, France, informally referred to as an onychophoran for more than 30 years. The onychophoran affinities of Antennipatus montceauensis gen. nov., sp. nov. are indicated by the form of the trunk plicae and the shape and spacing of their papillae, details of antennal annuli, and the presence of putative slime papillae. The poor preservation of several key systematic characters for extant Onychophora, however, prohibits the precise placement of the Carboniferous fossil in the stem or crown of the two extant families, or the onychophoran stem‐group as a whole. Nevertheless, A. montceauensis is the most compelling candidate to date for a terrestrial Paleozoic onychophoran.     

Phylogenetic topology and timing of New Zealand olive shells are consistent with punctuated equilibrium

The olive shells of the genus Amalda comprises readily recognized species of marine neogastropod mollusks found around the world. The New Zealand Amalda fauna has particular notoriety as providing one of the best demonstrations of evolutionary morphological stasis, a prerequisite for punctuated equilibrium theory. An excellent fossil record includes representation of three extant endemic Amalda species used to explore patterns of form change. However, the phylogenetic relationship of the New Zealand Amalda species and the timing of their lineage splitting have not been studied, even though these would provide valuable evidence to test predictions of punctuated equilibrium. Here, we use entire mitogenome and long nuclear rRNA gene cassette data from 11 Amalda species, selected from New Zealand and around the world in light of high rates of endemicity among extant and fossil Amalda. Our inferred phylogenies do not refute the hypothesis that New Zealand Amalda are a natural monophyletic group and therefore an appropriate example of morphological stasis. Furthermore, estimates of the timing of cladogenesis from the molecular data for the New Zealand group are compatible with the fossil record for extant species and consistent with expectations of punctuated equilibrium.     

Discrimination of extant Pan species and subspecies using the enamel–dentine junction morphology of lower molars

Previous research has demonstrated that species and subspecies of extant chimpanzees and bonobos can be distinguished on the basis of the shape of their molar crowns. Thus, there is potential for fossil taxa, particularly fossil hominins, to be distinguished at similar taxonomic levels using molar crown morphology. Unfortunately, due to occlusal attrition, the original crown morphology is often absent in fossil teeth, and this has limited the amount of shape information used to discriminate hominin molars. The enamel–dentine junction (EDJ) of molar teeth preserves considerable shape information, particularly in regard to the original shape of the crown, and remains present through the early stages of attrition. In this study, we investigate whether the shape of the EDJ of lower first and second molars can distinguish species and subspecies of extant Pan. Micro‐computed tomography was employed to non‐destructively image the EDJ, and geometric morphometric analytical methods were used to compare EDJ shape among samples of Pan paniscus (N = 17), Pan troglodytes troglodytes (N = 13), and Pan troglodytes verus (N = 18). Discriminant analysis indicates that EDJ morphology distinguishes among extant Pan species and subspecies with a high degree of reliability. The morphological differences in EDJ shape among the taxa are subtle and relate to the relative height and position of the dentine horns, the height of the dentine crown, and the shape of the crown base, but their existence supports the inclusion of EDJ shape (particularly those aspects of shape in the vertical dimension) in the systematic analysis of fossil hominin lower molars. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.     

Spore wall ultrastructure in the early lycopsid Leclercqia (Protolepidodendrales) from the Lower Devonian of North America: Evidence for a fundamental division in the lycopsids

Documenting the morphology and ultrastructure of spores from known Silurian-Devonian plants clarifies organization and probable affinities of dispersed spores and contributes to analyses of evolutionary changes and phylogenetic relationships in early plants. In this study of fossil in situ spores from the early protolepidodendralean lycopsid Leclercqia, we identified new characters including an additional synapomorphy of the ligulate lycopsid clade. A detailed light (LM), scanning electron (SEM), and transmission electron microscope (TEM) analysis of spores from two species of Leclercqia from the Lower Devonian (Emsian) of New Brunswick, eastern Canada, L. andrewsii and L. complexa, shows both are homosporous, yielding spores belonging to the dispersed spore form taxon Acinosporites lindlarensis. Important features of wall ultrastructure include the presence of a paraexospore, peculiar exospore-derived, peg-like structures located in the gap between the outer exospore/inner paraexospore, and multilamellate regions in the interradial areas of the proximal surface. Similar interradial multilamellate regions occur in other ligulate lycopsids (fossil and extant). This character is probably a further synapomorphy for the ligulate lycopsid clade, within which heterosporous lycopods form a monophyletic group. These data suggest the ligule and interradial multilamellate region appeared prior to heterospory.     

Ancient DNA from an extinct Mediterranean micromammal—Hypnomys morpheus (Rodentia: Gliridae)—Provides insight into the biogeographic history of insular dormice

The dormice (Gliridae) are a family of rodents represented by relatively few extant species, though the family was much more species-rich during the Early Miocene. Intergeneric phylogenetic relationships among glirids in some cases remain unresolved, despite extensive molecular and morphological analyses. Uncertainty is greatest with respect to the relationships among fossil taxa and how extinct lineages are related to modern species. The fossil genus Hypnomys from the Balearic Islands (western Mediterranean Sea) includes the Late Pleistocene–Holocene species Hypnomys morpheus, which has variously been considered a close relative or subgenus of the extant Eliomys. In the present study, we sequenced ancient mitochondrial DNA from H. morpheus, which suggests a sister relationship with the extant members of Eliomys. In addition, the pairwise sequence variation between Hypnomys and Eliomys is higher than that observed between congeneric glirid species (e.g., many Graphiurus spp.), which allows us to reject the hypothesis that Hypnomys is a subgenus of Eliomys. Our molecular dating analyses suggest that Hypnomys and Eliomys diverged 13.67 million years ago (95% highest posterior density [HPD] = 7.39–20.07). The relatively early split between these genera together with the molar morphology of early representatives of Hypnomys points to a Middle-Late Miocene origin from a continental glirid with a complex molar pattern, such as Vasseuromys or a closely related genus.     

How long can insect species exist? Evidence from extant and fossil Micromalthus beetles (Insecta: Coleoptera)

Six new fossils of Micromalthus (Coleoptera: Archostemata) from Dominican amber are compared with extant and previously described fossil micromalthid beetles. The amber inclusions are well preserved and all important morphological features are visible. Taking into account the morphological variability of the extant species Micromalthus debilis LeConte, 1878 , it is not possible to find any morphological features that distinguish the fossils from the extant species. This also applies to the Dominican amber inclusion described as Micromalthus anasi Perkovsky, 2008, which therefore is considered a junior synonym of M. debilis. The lack of morphological change in M. debilis over time might possibly be explained by unusually stable environmental conditions, as this species occupies a very specialized ecological niche in decaying timber. A general survey of fossil insects indistinguishable from extant species is presented. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158 , 300–311.     

Macrosiagon deuvei n. sp. (Coleoptera: Ripiphoridae) from the French Eocene amber

Macrosiagon deuvei n. sp., the second fossil representative of this extant genus of Ripiphoridae: Ripiphorinae: Macrosiagonini is described from the lowermost Eocene amber of Oise (France). The new species is compared with the extant species of the genus. Taxonomic position of other two fossil representatives of the family described from France by Perrichot et al. (2004) is discussed. The genus Paleoripiphorus Perrichot et al. 2004 is tentatively transferred from Ripiphorinae to Ripidiinae.     

A fossil heron from the early Oligocene of Belgium: the earliest temporally well‐constrained record of the Ardeidae

We describe the earliest temporally well‐constrained fossil that can be assigned to the Ardeidae (herons), from the lowermost Oligocene (32.0–33.0 million years ago) of Belgium. The specimen, a partial tarsometatarsus, belongs to a small species and is described as Proardea? deschutteri n. sp. It exhibits the characteristic tarsometatarsus morphology found in extant heron species, but a confident assignment to one of the ardeid subclades is not possible and even the assignment of the new fossil species to the crown group (the clade including the extant species) cannot be established. The fossil indicates a divergence of herons from their sister taxon by at least the earliest Oligocene, and current paleontological data suggest that herons arrived in Europe shortly after a major faunal turnover at the Eocene/Oligocene boundary. We consider that dispersal is the likely reason for the sudden appearance of herons in the earliest Oligocene of Europe but it is uncertain from where exactly this took place, with Asia and Africa being among the candidate areas.     

Inflorescence bracts of fossil and extant Tilia in North America,Europe, and Asia: patterns of morphologic divergence and biogeographic history

The enlarged inflorescence bract diagnostic of extant Tilia has an extensive Tertiary fossil record in the Northern Hemisphere. Diversity of bract morphology, and the extent of adnation between peduncle and bract, is reviewed for fossil and extant species of Tilia. An extinct type of bract with an orbicular outline and palmate venation is documented by the fossil species Tilia circularis (Chaney) comb. nov. from the early Oligocene of Oregon and is designated Type A. Living species of the genus have elongate bracts with predominately pinnate venation that are borne in two basic configurations: Type B, with the peduncle fused only to the extreme base of the bract lamina, as in extant Tilia endochrysea Hand.-Mzt. of southern China; and Type C with the peduncle fused medially along the basal one-third of the bract lamina, as in most extant species. Bracts of Type B were widely distributed in the Tertiary of western North America (late Eocene to Miocene) and Europe (early Miocene to Pliocene), while those of Type C are known in the fossil condition only from the middle and late Tertiary of Asia and Pliocene of Europe. The bracts of T. circularis, like those of type B, are borne on relatively long stalks and have the peduncle fused only at the extreme base. The fossil record supports recognition of the following characters as apomorphic in Tilia bract evolution: bracts sessile, peduncle adnate to the upper surface of the bract, and pinnate bract venation.