The geologic history of the Lythraceae

The known fossil record of the Lythraceae has been amplified by recent studies in northern Latin America. A total of 18 genera is recognized in geologic strata ranging in age from lower Eocene to Recent, and among the 22 or 23 modern genera, seven have a documented geologic history. The oldest remains are from an Indo-Malayan Old World warm-temperate to subtropical vegetation preserved in the lower Eocene London Clay flora. The most ancient of extant genera isLagerstroemia and the most recent (among those with an adequate fossil record) isCuphea (middle Miocene to Recent). These represent, respectively, primitive and advanced members of the family, and the paleobotanical record supports current concepts concerning phylogenetic relationships among genera of the Lythraceae. The family apparently had an Old World origin and became differentiated into a distinct modern taxon during Paleocene and early Eocene time.     

Fossil moonseeds from the Paleogene of West Gondwana (Patagonia,Argentina)

Premise of the Study

The fossil record is critical for testing biogeographic hypotheses. Menispermaceae (moonseeds) are a widespread family with a rich fossil record and alternative hypotheses related to their origin and diversification. The family is well‐represented in Cenozoic deposits of the northern hemisphere, but the record in the southern hemisphere is sparse. Filling in the southern record of moonseeds will improve our ability to evaluate alternative biogeographic hypotheses.

Methods

Fossils were collected from the Salamanca (early Paleocene, Danian) and the Huitrera (early Eocene, Ypresian) formations in Chubut Province, Argentina. We photographed them using light microscopy, epifluorescence, and scanning electron microscopy and compared the fossils with similar extant and fossil Menispermaceae using herbarium specimens and published literature.

Key Results

We describe fossil leaves and endocarps attributed to Menispermaceae from Argentinean Patagonia. The leaves are identified to the family, and the endocarps are further identified to the tribe Cissampelideae. The Salamancan endocarp is assigned to the extant genus Stephania. These fossils significantly expand the known range of Menispermaceae in South America, and they include the oldest (ca. 64 Ma) unequivocal evidence of the family worldwide.

Conclusions

Our findings highlight the importance of West Gondwana in the evolution of Menispermaceae during the Paleogene. Currently, the fossil record does not discern between a Laurasian or Gondwanan origin; however, it does demonstrate that Menispermaceae grew well outside the tropics by the early Paleocene. The endocarps’ affinity with Cissampelideae suggests that diversification of the family was well underway by the earliest Paleocene.     

Fossil Nelumbonaceae from the La Colonia Formation (Campanian–Maastrichtian,Upper Cretaceous), Chubut,Patagonia, Argentina

We describe here fossil leaves and fruits assignable to the family Nelumbonaceae Dumortier 1828. Fossils were collected at the Cañadón del Irupé locality, La Colonia Formation (Campanian–Maastrichtian, Upper Cretaceous), Chubut Province, Patagonia, Argentina. The fossil leaves are simple, with symmetrical and peltate lamina, orbicular in shape, and an entire margin. The venation is truly actinodromous with at least 15 primary veins, the secondary veins are poorly developed and intercalated with the primary veins, the third category vein is opposite, and the areoles are well-developed and 4- to 5-sided. These features are characteristic of the extant genus Nelumbo Adamson 1763, and the presence of these characters in the fossils allows their placement within this genus. Reproductive structures, similar to the fruit-receptacle of Nelumbo with fruits in situ, were found associated but not in organic connection with the leaves. These fossils constitute the only and oldest record for the family in the Southern Hemisphere. This record indicates that Nelumbo was more widespread in the past than today.     

基于叶绿体基因组探讨桃金娘目及其近缘类群的系统发育关系

该研究基于叶绿体基因组数据,对桃金娘目(6科44属97种)及其近缘类群(牻牛儿苗目2科5属25种)的系统发育关系进行了分析.结果表明:(1)桃金娘目基因组大小为152～171 kb,包括的蛋白质编码基因数目为74～90个;牻牛儿苗目基因组大小为116～242 kb,包括的蛋白质编码基因数目为75～132个.(2)对比叶...     

Early Paleogene decapod crustaceans from the Sulaiman and Kirthar Ranges,Pakistan

A set of Paleocene and Eocene decapod crustaceans is described from the Sulaiman and Kirthar Ranges of Pakistan. The fossil crabs Proxicarpilius planifrons Collins and Morris, 1978 and Pakicarcinus orientalis (Collins and Morris, 1978), already known in the Eocene of northern Pakistan, are reported for the first time in the Paleocene of southern Pakistan, enlarging the stratigraphic and the palaeobiogeographical ranges of these species. The callianassid genus Calliax de Saint Laurent, 1973 is reported for the first time in the Paleocene of southern Pakistan; this is the oldest record for the genus.     

The oldest Odontostomidae (Mollusca: Gastropoda): Bahiensis priscus n.?sp. (Paleocene, Uruguay)

The land snail family Odontostomidae has a poor fossil record, mainly from the middle Paleogene and early Neogene of Argentina. In this paper a new species of Odontostomidae from the Paleocene of Uruguay (Queguay Formation) is described. Bahiensis priscus n.?sp. represents the first record of the genus Bahiensis Jousseaume 1877, and the oldest record for an Odontostomidae. The new species is characterized by a pupoid fusiform shell and an oval aperture with a single axial columellar fold. Present distribution of the genus indicates a tropical?Csubtropical environment, in high humidity rate areas.     

PALYNOLOGY AND SYSTEMATICS OF THE LYTHRACEAE. II. GENERA HAITIA THROUGH PEPLIS

Pollen morphology for 12 genera of the Lythraceae is described, using light microscopy (LM), scanning (SEM) and transmission electron microscopy (TEM). The genera surveyed are Haitia, Heimia, Hionanthera, Lafoensia, Lagerstroemia, Lawsonia, Lythrum, Nesaea, Orias (= Lagerstroemia), Pehria, Pemphis, and Peplis. Among results of taxonomic significance are 1) the similarity of pollen between Haitia and Ginoria, suggesting that future classifications reflect a close relationship between these genera, 2) a comparable similarity in pollen between Pehria and Adenaria, 3) the distinction of Hionanthera pollen from that of Ammannia, 4) an exine similar in certain ultrastructural characteristics between Orias and some species of Lagerstroemia, although in general aspect they appear quite different, 5) that within the Didiplis-Lythrum-Peplis complex, there are three palynologically distinct groups, with Didiplis standing apart from the somewhat more similar, but nevertheless, distinct Lythrum and Peplis, and 6) that considerable differences exist between pollen of Pemphis acidula and Pemphis madagascariensis, supporting removal of the latter species to a new genus. This pollen survey is part of a multi-disciplinary effort to clarify generic limits in the Lythraceae, and evaluate relationships within the family and among families of the Myrtales.     

PALYNOLOGY AND SYSTEMATICS OF THE LYTHRACEAE. III. GENERA PHYSOCALYMMA THROUGH WOODFORDIA,ADDENDA, AND CONCLUSIONS

Pollen of the 27 genera presently recognized as comprising the family Lythraceae have been surveyed with light microscopy and scanning and transmission electron microscopy. Results for five genera (Physocalymma, Pleurophora, Rotala, Tetrataxis, Woodfordia), in addition to Duabanga, Sonneratia, and Punica (assigned to the Lythraceae in some classifications), are presented here; the remaining genera were treated previously in the series. The family is revealed as the most diverse palynologically of the order Myrtales. The most simple pollen type and the one common to the largest number of genera is prolate-spheroidal to prolate; tricolporate, without pseudocolpi; psilate, scabrate or finely verrucate; and 16–28 μm or less in length. Specializations include oblate grains, development of pseudocolpi (three or six in number), diversification of exine sculpturing, broadening of the colpal and pseudocolpal areas, and reduction in the conspicuousness of the colpi. Pollen evidence provides qualified support for inclusion of Punica in the Lythraceae, the generalized nature of the pollen tempering the conclusion, and little support for inclusion of Sonneratia and Duabanga in the family. Completion of the survey provides a data base of pollen characters that will be integrated in future studies with other evidence into an overall phenetic and cladistic assessment of the family leading to production of a more natural classification.     

FOSSIL CERATOPHYLLUM (CERATOPHYLLACEAE) FROM THE TERTIARY OF NORTH AMERICA

Fossil fruits and a vegetative axis assignable to the extant genus Ceratophyllum are described from four North American Tertiary localities. Fossil fruits assignable to the extant species C. muricatum and C. echinatum are reported from the Eocene Green River and Claiborne formations, and the Miocene Esmerelda Formation, respectively. An extinct species, C. furcatispinum, is described from the Paleocene Fort Union Formation and represents the oldest published report of Ceratophyllum in the fossil record. The existence of extant angiosperm species in the Eocene is very unusual and may be attributable in this case to slow evolutionary rates and unusual evolutionary properties associated with hydrophily in the genus Ceratophyllum.     

Oldest occurrence of the genusStegoceras (Dinosauria: Pachycephalosauridae) from the Foremost Formation (Campanian) of South Alberta, Canada

Three pachycephalosaurid frontoparietals from the Foremost Formation (Campanian) of South Alberta, Canada, are described and assigned to the genusStegoceras Lambe 1902 on the basis of measurements. Measurements and indices suggest that all of the specimens originate from male animals. The specimens are the oldest fossil record of this genus. The possibility is discussed, that they represent a species that could be an ancestor of the North AmericanStegoceras validum and/or the MongolianPrenocephale prenes.     

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.     

Where to Dig for Fossils: Combining Climate-Envelope,Taphonomy and Discovery Models

Fossils represent invaluable data to reconstruct the past history of life, yet fossil-rich sites are often rare and difficult to find. The traditional fossil-hunting approach focuses on small areas and has not yet taken advantage of modelling techniques commonly used in ecology to account for an organism’s past distributions. We propose a new method to assist finding fossils at continental scales based on modelling the past distribution of species, the geological suitability of fossil preservation and the likelihood of fossil discovery in the field, and apply it to several genera of Australian megafauna that went extinct in the Late Quaternary. Our models predicted higher fossil potentials for independent sites than for randomly selected locations (mean Kolmogorov-Smirnov statistic = 0.66). We demonstrate the utility of accounting for the distribution history of fossil taxa when trying to find the most suitable areas to look for fossils. For some genera, the probability of finding fossils based on simple climate-envelope models was higher than the probability based on models incorporating current conditions associated with fossil preservation and discovery as predictors. However, combining the outputs from climate-envelope, preservation, and discovery models resulted in the most accurate predictions of potential fossil sites at a continental scale. We proposed potential areas to discover new fossils of Diprotodon, Zygomaturus, Protemnodon, Thylacoleo, and Genyornis, and provide guidelines on how to apply our approach to assist fossil hunting in other continents and geological settings.     

广东南雄古新世一新的裂齿类

记述了广东南雄盆地早～中古新世上湖组上部发现的裂齿目一新属新种──杨氏华南兽（Ｈｕａｎａｎｉｕｓ ｙｏｕｎｇｉ ｇｅｎ． ｅｔ ｓｐ． ｎｏｖ．）。新属在上、下前日齿不臼齿化,上臼齿无次尖,下臼齿三角座和跟座均呈Ｖ形等方面显得原始。但在颊齿单面高冠,上臼齿原尖前、后脊分别与前、后附尖相连,小尖发育,具初始的次尖架,下臼齿略呈双曲拱柱状,具下后附尖等方面显示了向典型的裂齿类方向发展。     

The earliest fossil record of the extant rove beetle genus Phloeocharis from mid-Cretaceous Kachin amber of northern Myanmar and its biogeographic implications (Coleoptera: Staphylinidae: Phloeocharinae)

Phloeocharis Mannerheim is the largest genus within the problematic rove beetle subfamily Phloeocharinae, with a single extinct and 44 recent species recorded from the Holarctic Region. Until now, the oldest fossil record of Phloeocharis was known from Late Cretaceous (Turonian) amber from New Jersey, USA. Here we describe 2Phloeocharis burmana n. sp. from mid-Cretaceous (Albian–Cenomanian) Kachin amber from northern Myanmar, as the earliest extinct species of this genus. Our finding also sheds light on the biogeography of Phloeocharis, since no recent or extinct species have so far been recorded from the Oriental Region. Furthermore, the discovery of 2P. burmana n. sp. extends the Mesozoic diversity of the phloeocharine rove beetles both taxonomically and morphologically, particularly from Kachin amber.     

Evidence for a pre-PETM dispersal of the earliest European crocodyloids

Crocodyloid remains from the late Paleocene of Mont de Berru (France) hosted in the collections of the Muséum National d’Histoire Naturelle (Paris, France) and in the Institut royal des Sciences naturelles de Belgique (Brussels, Belgium) are described for the first time. This material, although fragmentary, can be clearly referred on a morphological basis to Asiatosuchus depressifrons (Blainville, 1855), a species previously reported from several Eocene Belgian localities thanks to abundant material including a nearly complete skeleton. The Paleocene material shares with A. depressifrons the number of alveoli involved in the dentary symphysis, the exclusion of the splenials from the symphysis, and the presence of a distinct depression on the jugal. The fossil remains from Berru represent the oldest European crocodyloid. Along with the alligatoroid Diplocynodon remensis Martin, Smith, de Lapparent de Broin, Escuillié and Delfino, 2014, previously reported from the same locality, the crocodyloid A. depressifrons indicates that these genera reached Europe before the Paleocene–Eocene Thermal Maximum. Although more complete remains from outside Europe are needed to refine phylogenetic hypotheses, according to the currently established fossil record the forerunners of diplocynodontids likely dispersed from North America, whereas those related to Asiatosuchus likely dispersed from Asia.     

PTEROCARYOID FRUITS (JUGLANDACEAE) IN THE PALEOGENE OF NORTH AMERICA AND THEIR EVOLUTIONARY AND BIOGEOGRAPHIC SIGNIFICANCE

The Juglandaceae (walnut family) has an excellent fossil record of various organs extending back to the earliest Tertiary. Several genera which today are restricted to isolated geographic regions were widespread in the Northern Hemisphere during the Tertiary. This paper focuses upon the fossil record of the Pterocarya alliance of the subfamily Juglandoideae, tribe Juglandeae. The Pterocarya alliance includes only two modern genera, Pterocarya (five species) and Cyclocarya (one species), both restricted to Eurasia. Paleogene sediments of the Rocky Mountain Region have yielded three genera and four species referable to the Pterocarya alliance: Cyclocarya (two species), Pterocarya, and a new genus, Polyptera. Although three of the four Paleogene species described here are attributed to present day genera, each represents an extinct form, which cannot be accommodated by any single living species. These fossils, reviewed with other published reports, indicate that the Pterocarya alliance, like the Engelhardia alliance of the same family, was more diverse and much more widespread geographically in the Tertiary than it is today.     

Systematic revision of Siwalik Rhizomyidae (Rodentia)

Larges samples of fossil rhizomyids from the Siwalikmolasse deposits of the Potwar Plateau, Pakistan, enable reevaluation of fossil taxa and their evolutionary relationships. Siwalik Rhizomyidae constitute a basis for analysis of poorly represented rhizomyids from other areas in Asia and contribute to biochronological correlation. The extant Tachyoryctinae and Rhizomyinae diverged during the early history of the family and diagnoses of the subfamilies are amended to include extinct genera. Siwalik tachyoryctines include Kanisamys, Protachyoryctes, Rhizomyides, and Eicooryctes nov. gen.; rhizomyines are Brachyrhizomys and Anepsirhizomys nov. gen. Kanisamys, the earliest Siwalik rhizomyid, appeared by about 13 Ma and evolved slowly, displaying stasis in K. sivalensis. Brachyrhizomys evolved from Kanisamys by 9.5 Ma and radiated rapidly. B. nagrii displays rapid increase in size through time. About 7 Ma, Kanisamys and Brachyrhizomys became extinct locally and Protachyoryctes, Eicooryctes, and Rhizomyides appeared, perhaps in response to increasing aridity. After 5.5 Ma, rhizomyids became uncommon in the Potwar and Anepsirhizomys (3.0 Ma) constitutes the latest record of Rhizomyidae in Pakistan.     

Diversity of Menispermaceae from the Paleocene and Eocene of South China

We present here the earliest known Asian fossil records of the Menispermaceae based on fossil fruits from Paleocene and Eocene localities in South China. A new genus and species, Paleoorbicarpum parvum sp. nov., and two new species of Stephania Loureiro, S. ornamenta sp. nov. and S. geniculata sp. nov., are recognized from Paleocene deposits of the Sanshui Basin, Guangdong, and a new occurrence of the widespread Eocene species Stephania auriformis (Hollick) Han & Manchester is recognized from the Maoming Basin, Guangdong. The Paleocene Stephania specimens described here represent the earliest fossil endocarp record of the Menispermaceae in eastern Asia. This discovery shows that the moonseed family had arrived in tropical and humid South China by at least the middle Paleocene, which provides important evidence for the origin and phytogeographic history of the family.     

Anatomically preserved seeds of Nuphar (Nymphaeaceae) from the Early Eocene of Wutu, Shandong Province, China

Well-preserved seeds from the early Eocene of Wutu, Shandong, China are assigned to the genus Nuphar (Nymphaeaceae) based on morphology and anatomy. The seeds of Nuphar wutuensis sp. nov. are ellipsoidal to ovoid, 4-5 mm long with a clearly visible raphe ridge, and a truncate apex capped by a circular operculum ca. 1 mm in diameter bearing a central micropylar protrusion. These features, along with the testa composed of a uniseriate outer layer of equiaxial pentagonal to hexagonal surface cells and a middle layer 4-6 cells thick composed of thick-walled, periclinally elongate sclereids, correspond to the morphology and anatomy of extant Nuphar and distinguish this fossil species from all other extant and extinct genera of Nymphaeales. These seeds provide the oldest record for the genus in Asia and are supplemented by a similar well-preserved specimen from the Paleocene of North Dakota, USA. These data, together with the prior recognition of Brasenia (Cabombaceae) in the middle Eocene, indicate that the families Nymphaeaceae and Cabombaceae had differentiated by the early Tertiary.