David L. Dilcher

The evolutionary convergence of mid-Mesozoic lacewings and Cenozoic butterflies

Mid-Mesozoic kalligrammatid lacewings (Neuroptera) entered the fossil record 165 million years ago (Ma) and disappeared 45 Ma later. Extant papilionoid butterflies (Lepidoptera) probably originated 80–70 Ma, long after kalligrammatids became extinct. Although poor preservation of kalligrammatid fossils previously prevented their detailed morphological and ecological characterization, we examine new, well-preserved, kalligrammatid fossils from Middle Jurassic and Early Cretaceous sites in northeastern China to unravel a surprising array of similar morphological and ecological features in these two, unrelated clades. We used polarized light and epifluorescence photography, SEM imaging, energy dispersive spectrometry and time-of-flight secondary ion mass spectrometry to examine kalligrammatid fossils and their environment. We mapped the evolution of specific traits onto a kalligrammatid phylogeny and discovered that these extinct lacewings convergently evolved wing eyespots that possibly contained melanin, and wing scales, elongate tubular proboscides, similar feeding styles, and seed–plant associations, similar to butterflies. Long-proboscid kalligrammatid lacewings lived in ecosystems with gymnosperm–insect relationships and likely accessed bennettitalean pollination drops and pollen. This system later was replaced by mid-Cretaceous angiosperms and their insect pollinators.

Phylogeographic analysis reveals significant spatial genetic structure of Incarvillea sinensis as a product of mountain building

BackgroundIncarvillea sinensis is widely distributed from Southwest China to Northeast China and in the Russian Far East. The distribution of this species was thought to be influenced by the uplift of the Qinghai-Tibet Plateau and Quaternary glaciation. To reveal the imprints of geological events on the spatial genetic structure of Incarvillea sinensis, we examined two cpDNA segments ( trnH- psbA and trnS- trnfM) in 705 individuals from 47 localities.ResultsA total of 16 haplotypes was identified, and significant genetic differentiation was revealed (GST =0.843, NSTu2009=u20090.975, Pu2009<u20090.05). The survey detected two highly divergent cpDNA lineages connected by a deep gap with allopatric distributions: the southern lineage with higher genetic diversity and differentiation in the eastern Qinghai-Tibet Plateau, and the northern lineage in the region outside the Qinghai-Tibet Plateau. The divergence between these two lineages was estimated at 4.4 MYA. A correlation between the genetic and the geographic distances indicates that genetic drift was more influential than gene flow in the northern clade with lower diversity and divergence. However, a scenario of regional equilibrium between gene flow and drift was shown for the southern clade. The feature of spatial distribution of the genetic diversity of the southern lineage possibly indicated that allopatric fragmentation was dominant in the collections from the eastern Qinghai-Tibet Plateau.ConclusionsThe results revealed that the uplift of the Qinghai-Tibet Plateau likely resulted in the significant divergence between the lineage in the eastern Qinghai-Tibet Plateau and the other one outside this area. The diverse niches in the eastern Qinghai-Tibet Plateau created a wide spectrum of habitats to accumulate and accommodate new mutations. The features of genetic diversity of populations outside the eastern Qinghai-Tibet Plateau seemed to reveal the imprints of extinction during the Glacial and the interglacial and postglacial recolonization. Our study is a typical case of the significance of the uplift of the Qinghai-Tibet Plateau and the Quaternary Glacial in spatial genetic structure of eastern Asian plants, and sheds new light on the evolution of biodiversity in the Qinghai-Tibet Plateau at the intraspecies level.

Coryphoid palm leaf fossils from the Maastrichtian-Danian of Central India with remarks on phytogeography of the Coryphoideae (Arecaceae).

Premise of research A large number of fossil coryphoid palm wood and fruits have been reported from the Deccan Intertrappean beds of India. We document the oldest well-preserved and very rare costapalmate palm leaves and inflorescence like structures from the same horizon. Methodology A number of specimens were collected from Maastrichtian–Danian sediments of the Deccan Intertrappean beds, Ghughua, near Umaria, Dindori District, Madhya Pradesh, India. The specimens are compared with modern and fossil taxa of the family Arecaceae. Pivotal results Sabalites dindoriensis sp. nov. is described based on fossil leaf specimens including basal to apical parts. These are the oldest coryphoid fossil palm leaves from India as well as, at the time of deposition, from the Gondwana- derived continents. Conclusions The fossil record of coryphoid palm leaves presented here and reported from the Eurasian localities suggests that this is the oldest record of coryphoid palm leaves from India and also from the Gondwana- derived continents suggesting that the coryphoid palms were well established and wide spread on both northern and southern hemispheres by the Maastrichtian–Danian. The coryphoid palms probably dispersed into India from Europe via Africa during the latest Cretaceous long before the Indian Plate collided with the Eurasian Plate.

Fertile structures with in situ spores of a dipterid fern from the Triassic in southern China.

Clathropteris was a typical dipterid fern with well documented fossil record and was widely dispersed during the Mesozoic; however, our knowledge of fertile structures including in situ spores for this genus is still very limited. Here we report well-preserved compression specimens of Clathropteris obovata Oishi from the Late Triassic of Guangyuan, Sichuan Province, China. The specimens show round to oval and exindusiate sori, vertical to oblique annuli in sporangia, and in situ trilete spores with verrucate and baculate sculptures, which are comparable to dispersed spore genera of Converrucosisporites and Conbaculatisporites. Comparisons of relevant fossil taxa suggest that specimens of C. obovata from Triassic of China provide for the first time in Asia the detailed fertile structures with in situ spore characters of dipterid fossil Clathropteris. Unlike living Dipteris, Mesozoic fossils of Dipteridaceae show a high diversity and a range of complex morphology of in situ spores, thus are significant for the evolutionary links between Dipteridaceae and other related fern clade, including Gleicheniaceae and Matoniaceae of the Gleicheniales.

Fruits, seeds, and flowers from the Warman clay pit (middle Eocene Claiborne Group), western Tennessee, USA

In this report, we examine fossil plant reproductive materials from the Warman clay pit in western Tennessee. The investigation of about 600 specimens has resulted in the recognition of 60 species and morphotypes. Based upon comparisons of gross morphology of these specimens with available extant plant materials and the literature, we have been able to assess their affinities with 16 extant families. We are able to relate 36 species and morphotypes to the following families: Altingiaceae, Annonaceae, Araceae, Araliaceae, Bignoniaceae, Euphorbiaceae, Fabaceae, Fagaceae, Hamamelidaceae, Juglandaceae, Lauraceae, Magnoliaceae, Malpighiaceae, Moraceae, Oleaceae, and Theaceae. In addition, 24 morphotypes are not assigned to any family due to the limited number of diagnostic characters. This report represents a comprehensive review on the reproductive materials from a single locality of the Claiborne Group of the southeastern United States. Compared to traditional investigations focused primarily on leaves, this study provides a different perspective for understanding plant diversity for the middle Eocene Claiborne Group. Hongshan Wang. Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611, USA hwang@flmnh.ufl.edu Jane Blanchard. Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611, USA Ojjhblanchard@aol.com David L. Dilcher. Departments of Biology and Geology, Indiana University, Bloomington, Indiana 47405, USA dilcher@indiana.edu

Palynological composition of a Lower Cretaceous South American tropical sequence: Climatic implications and diversity comparisons with other latitudes

PREMISE OF THE STUDYnReconstruction of floristic patterns during the early diversification of angiosperms is impeded by the scarce fossil record, especially in tropical latitudes. Here we collected quantitative palynological data from a stratigraphic sequence in tropical South America to provide floristic and climatic insights into such tropical environments during the Early Cretaceous.nnnMETHODSnWe reconstructed the floristic composition of an Aptian-Albian tropical sequence from central Colombia using quantitative palynology (rarefied species richness and abundance) and used it to infer its predominant climatic conditions. Additionally, we compared our results with available quantitative data from three other sequences encompassing 70 floristic assemblages to determine latitudinal diversity patterns.nnnKEY RESULTSnAbundance of humidity indicators was higher than that of aridity indicators (61% vs. 10%). Additionally, we found an angiosperm latitudinal diversity gradient (LDG) for the Aptian, but not for the Albian, and an inverted LDG of the overall diversity for the Albian. Angiosperm species turnover during the Albian, however, was higher in humid tropics.nnnCONCLUSIONSnThere were humid climates in northwestern South America during the Aptian-Albian interval contrary to the widespread aridity expected for the tropical belt. The Albian inverted overall LDG is produced by a faster increase in per-sample angiosperm and pteridophyte diversity in temperate latitudes. However, humid tropical sequences had higher rates of floristic turnover suggesting a higher degree of morphological variation than in temperate regions.

Accelerated evolution of early angiosperms: Evidence from ranunculalean phylogeny by integrating living and fossil data

The new discovery of angiosperm remains in the Jehol Biota of northeastern China contributes to our understanding of the origin and early evolution of flowering plants. The earliest eudicot genus with reproductive organs, Leefructus, was recently documented from the Lower Cretaceous Yixian Formation at 125.8–123.0 Ma, and was reconsidered to be close to the extant family Ranunculaceae based on gross morphology. However, this hypothesis has not been tested using a cladistic approach. To determine the possible allies of Leefructus within extant eudicots, we constructed a 66 morphological data matrix. Molecular and morphological analyses of extant Ranunculales combined with the fossil suggest that it has an affinity with the Ranunculaceae. The earliest fossil record of the eudicots is 127–125 Ma based on tricolpate pollen grains. Thus, we suggest a hypothesis that the basal eudicots might have experienced an accelerated evolution and diversification during the latest Barremian and earliest Aptian, leading to the stem groups of at least six extant families or lineages, 10–15 Myr earlier than currently documented. Angiosperms have undergone multiple uneven pulses of radiation since their origin. Many key character innovations occurred in different stages that could have triggered those radiations in concert with various biotic and abiotic factors.

Fruits, seeds and flowers from the Bovay and Bolden clay pits (early Eocene Tallahatta Formation, Claiborne Group), northern Mississippi, USA

This report is the second of a series of comprehensive reviews of the reproductive material from localities of the Eocene Claiborne Group of the southeastern United States. We examine fossil plant reproductive material from two localities, the Bovay and Bolden clay pits, in northern Mississippi, USA. The investigation of 193 specimens has resulted in the recognition of 52 taxa/morphotypes. Based upon comparisons of gross morphology of these specimens with available extant plant material and the literature, we are able to relate 17 taxa/morphotypes to the following 11 extant families: Annonaceae (1), Araliaceae (1), Caprifoliaceae (1), Eucommiaceae (1), Fabaceae (6), Fagaceae (2), Icacinaceae (1), Sapindaceae (1), Salicaceae (1), Rhamnaceae (1), and Theaceae (1). In addition, 35 morphotypes are not assigned to any family due to the limited number of diagnostic characters. Of the 52 taxa/morphotypes recognized, 38 (73.1%) are unique to the Bovay locality and nine (17.3%) are unique to Bolden. Only five (9.6%) taxa/morphotypes are shared by the two localities. Of the 62 taxa/morphotypes recognized from the Warman clay pit, Tennessee, only eight taxa/morphotypes are shared with the Bovay and/or Bolden localities, Mississippi. This study has expanded our knowledge of the Eocene plant diversity of the southeastern United States and has shown that there is a remarkable lack of species overlap among the three localities examined to date. Jane Blanchard. Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611, USA Ojjhblanchard@aol.com Hongshan Wang. Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611, USA hwang@flmnh.ufl.edu (corresponding author) David L. Dilcher. Departments of Biology and Geology, Indiana University, Bloomington, Indiana 47405, USA dilcher@indiana.edu

Paleocene Ipomoea (Convolvulaceae) from India with implications for an East Gondwana origin of Convolvulaceae

Significance The origin of the worldwide-distributed morning glory family (Convolvulaceae) has been a matter of debate. The fossil record from late Eocene sediments of North America argues for a Laurasian origin that is in contrast to a molecular phylogenetic study that favors an East Gondwana origin. This report of fossil Ipomoea from the late Paleocene of India supports the current molecular phylogenetic conclusions of an East Gondwana origin for Convolvulaceae. The morning glory family, Convolvulaceae, is globally important in medicine and food crops. The family has worldwide distribution in a variety of habitats; however, its fossil record is very poorly documented. The current fossil record suggests an origin in North America, which is in contrast to molecular data that indicate an East Gondwana origin. We report Ipomoea leaves from the late Paleocene (Thanetian; 58.7–55.8 million years ago) of India, which was a part of East Gondwana during this time. This is the earliest fossil record for both the family Convolvulaceae and the order Solanales. This suggests that the sister families Convolvulaceae and Solanaceae diverged before the Eocene in Gondwana-derived continents. The evidence presented here supports the conclusion from molecular phylogenetic analysis of an East Gondwana origin of Convolvulaceae.

Early Cretaceous angiosperm leaves from the Dakota Formation, Hoisington III locality, Kansas, USA

This study reports the results of an examination of about 1,500 fossil leaf impressions from the Early Cretaceous (Albian) strata at the Hoisington III locality, Kansas, USA. We recognize 24 fossil angiosperm leaf species, of which seven are assignable to the modern orders Illiciales (1), Laurales (4) and Magnoliales (2). Two species show close relationship with modern family Nymphaeaceae. Three species are possibly related to the Chloranthaceae. One species shows affinity with the Nelumbonaceae. Three species are closely related to the Platanaceae. One new genus, Wingia gen. nov., is established. A total of seven new species and new combinations are proposed. They include: Longstrethia aspera (Lesquereux) comb. nov., Sapindopsis powelliana (Lesquereux) comb. nov., Anisodromum schimperi (Lesquereux) comb. nov., Wingia expansolobum (Upchurch and Dilcher) comb. nov., Sapindopsis retallackii sp. nov., cf. Anisodromum upchurchii sp. nov., and Dicotylophyllum skogii sp. nov. Comparisons with the angiosperm leaf assemblages from other localities indicate that the Hoisington locality represents the most species-rich leaf assemblage from the Dakota Formation along the east side of the Cretaceous Western Interior Seaway (KWIS) and equivalent units. The result provides new information for understanding the early diversity and evolution of the angiosperms during the mid-Cretaceous (late Albian – early Cenomanian), a critical time during which angiosperms began a rapid adaptive radiation. Hongshan Wang. Florida Museum of Natural History, University of Florida, Gainesville, Florida 32611, USA. hwang@flmnh.ufl.edu David L. Dilcher. Department of Earth and Atmospheric Sciences, Indiana University, Bloomington, Indiana 47405, USA. dilcher@indiana.edu