Compression Fossils Research Articles

The age of North America’s youngest Paleozoic continental vertebrates: a review of data from the Middle Permian Pease River (Texas) and El Reno (Oklahoma) Groups

The youngest Paleozoic vertebrate-bearing continental deposits of North America are Middle Permian (Guadalupian) in age and occur in the Chickasha Formation (El Reno Group) of central Oklahoma and the lithostratigraphically lower San Angelo Formation (Pease River Group) of North-Central Texas. Although regarded originally as Guadalupian, these deposits have been assigned recently to the Early Permian on the basis of marine fossils and questionable lithostratigraphic correlations between marine and continental strata. A review of ammonoid genera recovered from the Blaine Formation, which overlies both the Chickasha and San Angelo in Oklahoma and Texas, shows that they range globally in age from the Early to Late Permian, but most occur in the Guadalupian or Middle Permian. A modest but intensively studied paleobotanical record of compression fossils from the San Angelo, as well as palynomorphs in rocks associated with the Chickasha, presents an unquestionably Middle to Late Permian flora dominated by voltzian conifers. The Chickasha and San Angelo vertebrate assemblages are overwhelmingly dominated by large caseid synapsids and indicate a biostratigraphic signal of early Guadalupian. The occurrence of the tupilakosaurid temnospondylSlaugenhopia, the parareptileMacroleter, and the eureptileRothianiscussuggests a Roadian age (lowermost Guadalupian) given the global records of closely related forms. These plant and vertebrate assemblages contrast sharply with those of underlying Cisuralian rocks of the Hennessey Formation of Oklahoma and the Clear Fork Formation of Texas, both of which are much more fossiliferous than those of the Guadalupian in the region. A barren interval of up to 300 m in thickness separates these fossil-bearing intervals. This true void in the late Kungurian was first reported a half century ago but has not been recognized in recent biochronology studies. Our findings, as well as those of other vertebrate paleontologists who have evaluated the San Angelo and Chickasha data by other means, strongly refute the current notion of “Olson’s Gap” as spanning most of the Roadian.

New grasshoppers (Orthoptera: Elcanidae, Locustopsidae) from the Lower Cretaceous Crato Formation suggest a biome homogeneity in Central Gondwana

ABSTRACT †Cratoelcana rasnitsyni sp. nov., new elcanid species, and †Pseudoacrida sennlaubi sp. nov., new locustopsid species, are described from the Lower Cretaceous Crato Formation in Brazil, on the basis of two well-preserved compression fossils. The genus †Cratoelcana previously comprised its type species †Cratoelcana zessini and †Cratoelcana damianii whose placement is doubtful and could belong to the Lower Cretaceous genus †Mimelcana from UK. The genus †Pseudoacrida was previously only known from the Lower Cretaceous of China. The pattern of colouration of the tegmen of †Cratoelcana rasnitsyni sp. nov. strongly differs from that of †Cratoelcana zessini. The presence of two rounded coloured or hyaline spots in the middle of the tegmen seems to be very frequent among the elcanid species. On the basis of the tegmen venation and pattern of colouration, there are probably no less than five different species of Elcanidae in the Crato Formation; two of them remain to be described. The palaeobiogeography of the †Elcanidae and †Locustopsidae are discussed, especially concerning for the Gondwana faunas.

A new genus and species of the subfamily Mirinae (Hemiptera: Cimicomorpha: Miridae) from Eocene Baltic amber with a new generic combination for Calocoris antennatus Statz in Statz & Wagner, 1950

A new fossil mirid, Baltiomiris herczeki gen. and sp. nov. is described from Eocene Baltic amber. Available morphological information is provided with photographs. Additionally, Calocoris antennatus Statz in Statz Wagner, 1950, a compression fossil, is transferred to the extant genus Mermitelocerus Reuter based on similarities of habitus, particularly of head structures.

Discovery of a new genus and species of Dryinidae (Hymenoptera: Chrysidoidea) from Kachin (Myanmar) amber: Rasnitsynum burmense gen. et sp. nov.

Dryinidae (Hymenoptera: Chrysidoidea) are parasitoids, and often also predators, of leafhoppers, planthoppers and treehoppers (Hemiptera: Auchenorrhyncha) (Guglielmino et al., 2013; Olmi et al., 2020b). Fossils of Dryinidae are known both as inclusions in amber and as compression fossils (Perkovsky et al., 2019; Olmi et al., 2010, 2020b; Martynova et al., 2020). Among the amber deposits, those situated in Myanmar are the richest. Mid-Cretaceous Burmese amber from Kachin State is known in fact to include Dryinidae belonging to the following subfamilies and genera: Anteoninae: Burmanteon Engel, 2003 (one species); Burmadryininae: Burmadryinus Olmi, Xu & Guglielmino, 2014 (one species); Dryininae: Dryinus Latreille, 1804 (12 species) (Martynova et al., 2020); Hybristodryinus Engel, 2005 (17 species) (Perkovsky et al., 2019; Tribull et al., 2020; Olmi et al., 2021; Wang et al., 2021); Pseudodryinus Olmi, 1991 (one species); Palaeoanteoninae: Palaeoanteon Olmi, 2000 (one species) (Perkovsky et al., 2020a); Raptodryininae: Raptodryinus Olmi, Perkovsky, Martynova, Contarini, Bückle, Guglielmino, 2020 (one species).

<p><strong>The recently proposed odonatan ‘suborder’ Cephalozygoptera: fact or fiction</strong></p>

The new ‘suborder’ Cephalozygoptera was recently proposed for three fossil families of damselfly-like Odonata, on the basis of three characters of the head. Here we show, thanks to counter-examples of the presence of these characters in compression fossils of genuine Zygoptera, that these ‘characters’ do not exist in reality but are due to deformations and compression of the heads, a very frequent phenomenon in the fossil record of the whole superorder Odonatoptera. Furthermore, these alleged characters would have to have been regarded as symplesiomorphies, insufficient to support a new clade. Consequently, we consider the Cephalozygoptera as unfounded, to be rejected in the current state of knowledge. A new phylogenetic analysis of the whole clade Panodonata would be welcome. We also discuss the position of some previously described fossils: the Paleocene genus Valerea is restored in the Epallagidae (Euphaeidae), and the two Burmese amber genera Electrodysagrion and Palaeodysagrion are restored in the family Dysagrionidae.

The first described turtle beetles from Eocene Baltic amber, with notes on fossil Chelonariidae (Coleoptera: Byrrhoidea)

Abstract. Chelonariidae, or turtle beetles, are rarely represented in the fossil record. Two new extinct species of this thermophilous coleopteran family, Chelonarium andabata Alekseev and Bukejs sp. nov. and Ch. dingansich Alekseev and Bukejs sp. nov., are described and illustrated from Eocene Baltic amber using X-ray micro-computed tomography (micro-CT). They are the first formally described species of turtle beetles from Eocene Baltic amber and the first known European representatives of this family. Based on modern habitats of the group, the presence of the plants with which their larvae are associated (epiphytic orchids) is proposed in the Eocene amber forest. The Eocene Florissant Formation fossil Chelonarium montanum Wickham, 1914, which was originally placed within Chelonariidae, is discussed based on its original description, and placement as incertae sedis within Byrrhoidea is proposed for this compression fossil (http://zoobank.org/References/C2EE164D-59DD-42FE-937D-B01C78DCD228, last access: 8 February 2021).

The second leafhopper of the subfamily Ledrinae (Hemiptera, Cicadellidae) in mid-Cretaceous Burmese amber

The cicadellid subfamily Ledrinae known in the Mesozoic is represented by two monotypic genera erected on six compression fossils from the Lower Cretaceous Crato Formation in Brazil, and the monotypic genus Qilia based on an adult leafhopper in mid-Cretaceous Kachin amber from northern Myanmar. We herein describe and illustrate a new female ledrine in Kachin amber, based on which a new genus and species, Duyana electronica gen. et sp. nov., is established. Duyana gen. nov. shares a series of features with the genus Qilia, but is distinguishable from the latter with some novel morphological characteristics. The hitherto definite cicadellid recorded in the Mesozoic are very scarce, and our find provides new information on early disparity of this mega-diverse insect lineage.

A remarkably complete skeleton from the London Clay provides insights into the morphology and diversity of early Eocene zygodactyl near-passerine birds

Recognition of the zygodactyl parrots (Psittaciformes) as the closest extant relatives of passerines (Passeriformes) shed new light on the affinities of various Paleogene birds with a zygodactyl foot, which are now considered to be stem group representatives of the Passeriformes. However, most of these taxa are known only from compression fossils, which allow the recognition of a limited number of osteological details. Here, an exceptionally complete skeleton of a new species is described from the early Eocene London Clay of Walton-on-the-Naze (Essex, UK). Parapsittacopes bergdahli gen. et sp. nov. resembles Psittacopes lepidus (Psittacopedidae) from the Messel fossil site in Germany, from which it is distinguished in beak shape and several postcranial characters. Even though the phylogenetic analyses yielded conflicting tree topologies under different settings, all of the resultant phylogenies supported close affinities between Parapsittacopes, Psittacopes and the Eocene taxa Pumiliornis and Morsoravis. The three-dimensionally preserved bones of the P. bergdahli holotype exhibit subtle osteological characteristics of passeriform birds, which have not been reported from previously known fossils of closely related zygodactyl stem group taxa. The broad beak and low mandibular rami indicate that P. bergdahli may have caught insects by sallying flights from perches, and the new species therefore adds another feeding adaptation to the already diverse array of zygodactyl stem group Passeriformes with disparate feeding ecologies. http://zoobank.org/urn:lsid:zoobank.org:pub:FD0E9DC4-961F-4460-9466-164E5EB42E4E

Eco-morphological diversity of larvae of soldier flies and their closest relatives in deep time.

Stratiomyomorpha (soldier flies and allies) is an ingroup of Diptera, with a fossil record stretching back to the Early Cretaceous (the Barremian, about 125 MYA). Stratiomyomorpha includes at least 3,000 species in the modern fauna, with many species being crucial for ecosystem functions, especially as saprophages. Larvae of many stratiomyomorphans are especially important as scavengers and saproxyls in modern ecosystems. Yet, fossil larvae of the group are extremely scarce. Here we present 23 new records of fossil stratiomyomorphan larvae, representing six discrete morphotypes. Specimens originate from Cretaceous amber from Myanmar, Eocene Baltic amber, Miocene Dominican amber, and compression fossils from the Eocene of Messel (Germany) and the Miocene of Slovenia. We discuss the implications of these new records for our understanding of stratiomyomorphan ecomorphology in deep time as well as their palaeoecology.

Identification of A Liverwort Fossil on Pottery from A Church Excavation in Northern Sudan: Evidence for Moist Paleoenvironment

This paper aims to document the first record of coalified compression fossil of a liverwort on pottery from a church excavation in the desert, northern Sudan. The outline or surface feature of the fossil is clearly observed. Morphological distortion is minimal while the internal anatomy is not preserved. The shapes of the archaeological specimens are closely similar to the morphology of a Riccia sp collected from the Red Sea state and the Blue Nile bank in Khartoum state. Energy-Dispersive X-ray fluorescence (EDXRF), Scanning Electron Microscopy with Energy (SEM/EDS), and Gas Chromatography and Mass Spectroscopy (GC-Mass) analytical techniques were used to determine the chemical composition of the fossil materials. Higher concentrations were reported for Carbon and Oxygen indicating the organic nature of the materials and also excluded the presence of manganese dentrites which perfectly imitate liverwort fossils. Also n-hexadecanoic acid, dodecanoic acid, tetradecanoic acid, hexadecanoic acid, methyl ester, cis-9-hexadecenoic acid, 9, 12-octadecadienoic acid (z,z)-, methyl ester,tert-butyldimethylsilyl decanoic acid were recorded for the fossil materials. This study also provides additions to the chemical profile for the fresh material from the same genus which provides important data or monitors for the assessment of the chemical or thermal alteration in the corresponding coalified compression fossil.

Visualizing mineralization processes and fossil anatomy using synchronous synchrotron X-ray fluorescence and X-ray diffraction mapping

Fossils, including those that occasionally preserve decay-prone soft tissues, are mostly made of minerals. Accessing their chemical composition provides unique insight into their past biology and/or the mechanisms by which they preserve, leading to a series of developments in chemical and elemental imaging. However, the mineral composition of fossils, particularly where soft tissues are preserved, is often only inferred indirectly from elemental data, while X-ray diffraction that specifically provides phase identification received little attention. Here, we show the use of synchrotron radiation to generate not only X-ray fluorescence elemental maps of a fossil, but also mineralogical maps in transmission geometry using a two-dimensional area detector placed behind the fossil. This innovative approach was applied to millimetre-thick cross-sections prepared through three-dimensionally preserved fossils, as well as to compressed fossils. It identifies and maps mineral phases and their distribution at the microscale over centimetre-sized areas, benefitting from the elemental information collected synchronously, and further informs on texture (preferential orientation), crystallite size and local strain. Probing such crystallographic information is instrumental in defining mineralization sequences, reconstructing the fossilization environment and constraining preservation biases. Similarly, this approach could potentially provide new knowledge on other (bio)mineralization processes in environmental sciences. We also illustrate that mineralogical contrasts between fossil tissues and/or the encasing sedimentary matrix can be used to visualize hidden anatomies in fossils.

First record of organic-walled microfossils from the Tonian Shiwangzhuang Formation of the Tumen Group in western Shandong, North China

Organic-walled microfossils offer important information on the biospheric evolution in pre-Cryogenian and provide biostratigraphic implications for many Proterozoic fossiliferous sequences that are poorly age constrained for the lack of reliable radiometric date. Recently, macroscopic carbonaceous compression fossils have been reported for the first time from the Tonian Shiwangzhuang Formation of the Tumen Group in western Shandong, North China. However, organic-walled microfossils have never been discovered from this formation up till now. To improve our knowledge about Proterozoic biodiversity in North China, we conducted a micropaleontological survey on the argillaceous limestone samples of the Shiwangzhuang Formation, which also contain macroscopic carbonaceous compression fossils, from the Baishicun section in Anqiu, western Shandong, North China. Our investigation shows that the Shiwangzhuang microfossil assemblage is dominated by smooth-walled sphaeromorphic acritarchs and cyanobacterium-like filaments and relatively low abundance of other acritarchs, including 16 taxa, such as Polysphaeroides filliformis, Ostiana microcystis, Simia annulare, ?Jacutianema sp., Arctacellularia tetragonala, Pellicularia tenera, Polythrichoides lineatus, and Navifusa actinomorpha. The Shiwangzhuang organic-walled microfossil assemblage, although consisting of long-ranging and not age diagnostic taxa, is consistent with a Tonian age suggested by macroscopic carbonaceous compression fossils, including the Chuaria-Tawuia and Sinosabellidites-Protoarenicola-Pararenicola assemblages, revealed from the same fossiliferous horizon of the Shiwangzhuang Formation and by organic-walled microfossil assemblage, including the late Mesoproterozoic to Tonian index fossil Trachyhystrichosphaera aimika, from the underlying Tongjiazhuang Formation. However, it is also worth noting that a Cryogenian or Ediacaran age cannot be completely excluded based just on the Shiwangzhuang microfossils because of their limited biostratigraphic utility.

An assemblage of macroscopic and diversified carbonaceous compression fossils from the Tonian Shiwangzhuang Formation in western Shandong, North China

Macroalgae play a crucial ecological and biogeochemical role in modern marine ecosystems. Although eukaryotic algae have a deep history within the Precambrian, most pre-Cryogenian alga fossils are microscopic and macroalga fossils are poorly documented during this period. Here we report a well-preserved assemblage of macroscopic and diversified carbonaceous compression fossils from the Tonian Shiwangzhuang Formation in western Shandong, North China. This assemblage consists of seventeen distinct morphotaxa, including eleven macroalgae, showing remarkable taxonomic diversity that is more diverse than many other Tonian macrofossil assemblages all over the world. Three taxa from the Shiwangzhuang assemblage show evidence of simple multicellularity with two of them consisting of giant cells and comparable to giant-celled green algae, and seven taxa with diagnostic transverse annulations are likely coenocytic algae. The Shiwangzhuang assemblage indicates that some eukaryotic clades had achieved macroscopic growth through simple multicellularity or coenocytism, paving the way, either ecologically or phylogenetically, for the eventual appearance of complex multicellularity. In addition, there are some biostratigraphically significant genera, including the Chuaria-Tawuia and Sinosabellidites-Protoarenicola-Pararenicola assemblages, indicating a Tonian age for the Shiwangzhuang Formation. This study also suggests that the Tonian diversity of multicellular or coenocytic macroalgae is probably underestimated, pending for a systematic and thorough investigation of Tonian macroscopic carbonaceous compressions. Macroalgae may have an initial ecological expansion, at least locally if not globally, in the Tonian Period.

A new Babinskaiidae from the mid-Cretaceous Burmese amber (Insecta, Neuroptera, Myrmeleontoidea)

We describe Parababinskaia douteaui sp. nov., second representative of its genus in the mid-Cretaceous Burmese amber. This genus was originally known after a compression fossil from the Brazilian Crato Formation. The five other Burmese amber genera of Babinskaiidae are currently endemic to this area. This Early Cretaceous antlion family remains unrecorded after the Cenomanian.

The Oldest Representative of the Rove Beetle Tribe Pinophilini (Coleoptera: Staphylinidae: Paederinae), from Upper Cretaceous Burmese Amber.

The recently reviewed subtribe Procirrina comprises eight extant genera with a predominately (sub)tropical distribution. Previous phylogenies consistently recover the tribe Pinophilini of the subfamily Paederinae monophyletic. No fossils of the tribe have been described, although compression fossils are known from the Cenozoic Green River Formation (50.3–46.2 Ma) as well as inclusions from the Miocene Dominican (20.43–13.65 Ma) and Mexican (20–15 Ma) ambers. Here we describe †Cretoprocirrus trichotos Jenkins Shaw and Żyła gen. et sp. n., the oldest fossil representative of the tribe Pinophilini, from Upper Cretaceous Burmese amber (ca. 99 Ma). Phylogenetic analyses of morphological data allow its unambiguous placement in the subtribe Procirrina. †Cretoprocirrus trichotos is the second genus of Paederinae described from Burmese amber and provides an important insight into the evolution of the subfamily.

PRESERVATION OF NEUROPTERIS OVATA IN ROOF SHALE AND IN FLUVIAL CREVASSE-SPLAY FACIES (LATE PENNSYLVANIAN, SYDNEY COALFIELD, CANADA). PART I: AN INFRARED-BASED CHEMOMETRIC MODEL

ABSTRACTAnalytical questions relating to the influence of sedimentation on the preservation states of Carboniferous plant fossils are seldom addressed in the literature. Here we address specifically the influence facies differences have on preservation states and suggest how they can be analyzed. The case study involves the seed fern Neuropteris ovata (Hoffmann) that occurs as opaque pinnules in the roof shale and as transparent pinnules in an associated crevasse-splay of the basal Cantabrian in age, Point Aconi Coal Seam, Sydney Coalfield, Canada. The color differences imply different molecular pathways for organic matter transformation over geological time, which resulted in production of compression fossils in the roof shale and fossilized-cuticle in the crevasse-splay, respectively. Fourier transform infrared spectroscopy methods are used to quantify functional groups, and the derived data are chemometrically evaluated. Results indicate that the compressions are, as anticipated, characterized in the crevasse-splay facies by a predominantly aromatic composition. The fossilized-cuticles, however, are mainly characterized by oxygen-containing aliphatics, confirming the influence of facies changes on preservation states of the species studied. Implications for preservation, taxonomy, and paleoecology are emphasized.

<p><strong>Specialized variegated mud-loving beetles from mid-Cretaceous Burmese amber (Coleoptera: Heteroceridae)</strong></p>

Variegated mud-loving beetles, or Heteroceridae, are a small family belonging to the polyphagan superfamily Byrrhoidea. To date, only two poorly preserved compression fossils have been known from the Early Cretaceous of Eurasia. Here we describe the first heterocerid beetles in mid-Cretaceous amber from northern Myanmar, Excavotarsus lini gen. et sp. nov. and Ex. minor sp. nov.. The two new fossil species are distinguished from all extant heterocerids by their elongate body shape, apical 8–9 antennomeres forming a loose serrate club, pronotum longer than wide, protibia lacking robust spines, and two-segmented protarsi. This peculiar combination of plesiomorphic and derived characters suggests that Excavotarsus represents an early-diverging lineage of Heteroceridae and indicates that the family originated and diversified before the mid-Cretaceous.

First fossil record of a jumping plant-louse (Insecta, Hemiptera, Psylloidea) from Japan

A fossil specimen of the jumping plant-louse genus Cacopsylla (Insecta, Hemiptera, Psylloidea) is described from lacustrine sediments of the middle Pleistocene Miyajima Formation of the Shiobara Group in Tochigi Prefecture, central Japan. It is the first report of a psylloid fossil from Japan. The specimen is a compression fossil of almost whole insect body, and the superb preservation of forewings with delicate veins and membrane tissues strongly suggests that it can be most probably identified as Cacopsylla abieti (Kuwayama), which is a common extant psyllid species in the fossil locality, or possibly its most closely relative of continental east Asia, Cacopsylla pseudosieboldiani (Konovalova and Loginova). The fossil-yielding stratum is a Lagerstatte known for the abundant fossil leaves and other fossil organisms. Extant C. abieti feeds on Siebold’s maple Acer sieboldianum, and remains of various species of Acer including A. sieboldianum are common components of Shiobara fossil biota.

Blera miocenica: a new species of Early Miocene hoverfly (Diptera: Syrphidae) from the Czech Republic and its palaeoenvironmental significance

A new species of fossil hoverfly (Syrphidae: Eristalinae), i.e., Blera miocenica sp. nov. is described from the Early Miocene (Burdigalian) of Bílina mine in the Most Basin, Czech Republic. The species description is based on a well preserved compressed fossil and it represents the first known fossil record of the genus Blera Billberg, 1820 so far. B. miocenica sp. nov. diagnosis is based on the wing venation and other body characters like the coloration pattern of abdomen. The resemblance of the new fossil to extant species of Blera is briefly discussed. The previously suggested palaeoenvironmental conditions at the type locality are in agreement with the knowledge on autecology of recent representatives of the genus Blera (i.e., larval feeding strategy, adult habitat preferences and flower visitation). Thus, we conclude that fossil hoverflies could be a helpful tool for the indication of past habitats.

Reliable placement of beetle fossils via phylogenetic analyses – Triassic Leehermania as a case study (Staphylinidae or Myxophaga?)

AbstractTriassic fossils are rare but crucial for understanding the early evolution of large insect clades including beetles (Coleoptera). Their phylogenetic assignment is problematic because of fragmentary preservation, yet crucial for the correct use of the information they provide. Here an analysis is presented of the phylogenetic position of Leehermania prorova, the Late Triassic compressed fossil which was described and hitherto widely used as the oldest representative of Staphylinidae (rove beetles) in the suborder Polyphaga. By contrast with the intuitive character assessment made in the original description, a phylogenetic analysis of Leehermania is performed using an extensive morphological matrix of extant Coleoptera provided by the Beetle Tree of Life project, constrained in view of the latest relevant molecular phylogenies. As a result, Leehermania is identified as an extinct lineage within the beetle suborder Myxophaga, closest to the modern family Hydroscaphidae. Excluding Leehermania from Staphylinidae and placing it in Myxophaga amends erroneous assumptions about early diversification of rove beetles and enhances our views of the evolutionary history of Coleoptera.