An unusual elateroid lineage from mid-Cretaceous Burmese amber (Coleoptera: Elateroidea)

We here report a new elateroid, Anoeuma lawrencei Li, Kundrata and Cai gen. et sp. nov., from mid-Cretaceous Burmese amber. Though superficially similar to some soft-bodied archostematans, Anoeuma could be firmly placed in the polyphagan superfamily Elateroidea based on the hind wing venation. Detailed morphological comparisons between extant elateroids and the Cretaceous fossils suggest that the unique character combination does not fit with confidence into any existing soft-bodied elateroid group, although some characters indicate possible relationships between Anoeuma and Omalisinae. Our discovery of this new lineage further demonstrates the past diversity and morphological disparity of soft-bodied elateroids.

The micro- and megafossil record of Nothofagaceae from South America

We compiled the numerous fossil records (486) assigned to Nothofagaceae including pollen grains (from surface sediments and continental and oceanic borehole cores), leaves, woods and reproductive structures from South America. All the records are revised and the latest systematic treatments and ages of the bearing strata of each record are followed. When possible, we proposed a subgeneric affinity to each record based on updated bibliography. Fossils of three (Nothofagus, Fuscospora and Lophozonia) of the four subgenera are found in similar proportions through time since the Late Cretaceous. Fossils with reliable affinity with subgenus Brassospora were not found in South America. Most of the records are concentrated in the southern tip of South America (Patagonia Region) and nearby areas. After a significant presence of Nothofagaceae in the Cretaceous, the family declined in diversity and abundance in the Palaeocene and then increased from the Eocene to the Miocene. In the Miocene, the records reach their maximum diversity and abundance, and Nothofagaceae usually dominate the assemblages of pollen, leaves and woods from Patagonia. Pliocene Nothofagaceae records are virtually absent, probably because sedimentary rocks of that age are rare in Patagonia. The fossil record for Nothofagaceae varies according to environmental turnover; when tropical/subtropical floras were present in Patagonia in the Palaeocene–early Eocene, Nothofagaceae contracted southwards and when open steppes developed in the Miocene of east Patagonia, Nothofagaceae contracted westward.

Angiosperms from the Early Cretaceous sediments of India

This study presents the first report of angiosperm macrofossil assemblage from the Early Cretaceous sediments of India, containing a fruit, a spike, a petal, leaves, and an axis from the Krishna Godavari Basin. This assemblage provides clues to angiosperm evolution and ecology during the Early Cretaceous of India. The described enigmatic forms are comparable to fruits of Trapa, and palm leaves and spikes of Potamogeton. The fossil material also includes ribbon-like leaves with a small axis; fossil remains suggest affinity with the monocotyledon group and support recent morphological and molecular phylogenetic studies to establish the divergence of this group from dicotyledons, during the early Cretaceous. Fossils described in the present study suggest an affinity for an aquatic environment that appears to be ideal for some early angiosperms.

Hunting the Snark: the flawed search for mythical Jurassic angiosperms

Several recent palaeobotanical studies claim to have found and described pre-Cretaceous angiosperm macrofossils. With rare exceptions, these papers fail to define a flower, do not acknowledge that fossils require character-based rather than group-based classification, do not explicitly state which morphological features would unambiguously identify a fossil as angiospermous, ignore the modern conceptual framework of phylogeny reconstruction, and infer features in the fossils in question that are interpreted differently by (or even invisible to) other researchers. This unfortunate situation is compounded by the relevant fossils being highly disarticulated two-dimensional compression-impressions lacking anatomical preservation. Given current evidence, all supposed pre-Cretaceous angiosperms are assignable to other major clades among the gymnosperms sensu lato. By any workable morphological definition, flowers are not confined to, and therefore cannot delimit, the angiosperm clade. More precisely defined character states that are potentially diagnostic of angiosperms must by definition originate on the phylogenetic branch that immediately precedes the angiosperm crown group. Although the most reliable candidates for diagnostic characters (triploid endosperm reflecting double fertilization, closed carpel, bitegmic ovule, and phloem companion cells) are rarely preserved and/or difficult to detect unambiguously, similar characters have occasionally been preserved in high-quality permineralized non-angiosperm fossils. The angiosperm radiation documented by Early Cretaceous fossils involves only lineages closely similar to extant taxonomic families, lacks obvious morphological gaps, and (as agreed by both the fossil record and molecular phylogenies) was relatively rapid—all features that suggest a primary radiation. It is unlikely that ancestors of the crown group common ancestor would have fulfilled a character-based definition of (and thereby required expansion of the concept of) an angiosperm; they would instead form a new element of the non-angiosperm members of the ‘anthophyte’ grade, competing with Caytonia to be viewed as morphologically determined sister group for angiosperms. Conclusions drawn from molecular phylogenetics should not be allowed to routinely constrain palaeobotanical inferences; reciprocal illumination between different categories of data offers greater explanatory power than immediately resorting to Grand Syntheses. The Jurassic angiosperm—essentially a product of molecular phylogenetics—may have become the holy grail of palaeobotany but it appears equally mythical.

A new crown wasp in mid-Cretaceous amber from northern Myanmar (Hymenoptera: Stephanidae)

The crown wasps, family Stephanidae, are generally believed to occupy a distinguished position as putative relicts of the earliest-diverging lineage of apocritan Hymenoptera (e.g., Sharkey et al., 2012; Mao et al., 2015). More recent analyses have cast some confusion over this hypothesis, with the family instead appearing closer to the Evanioidea or even Trigonalyoidea (Peters et al., 2017; Tang et al., 2019). From most analyses it is clear that the family extends well into the Cretaceous, with crown-group Stephanidae estimated to have appeared by at least the Early Cretaceous and a purported ghost-stem lineage extending into the Early Jurassic or even latest Triassic (Tang et al., 2019). At least parts of such a hypothesis are consistent with the number of mid-Cretaceous fossils representing a variety of crown wasps, including species of both the plesiomorphic subfamily Schlettereriinae as well as putative Stephaninae (Engel & Grimaldi, 2004; Engel et al., 2013; Engel & Huang, 2017; Li et al., 2017). Unfortunately, while such fossil occurrences are of considerable interest, the total available record of fossil crown wasps is poor, with most species documented from the Palaeogene (Engel, 2005; Engel & Ortega-Blanco, 2008), and hitherto only four species from the Late Cretaceous. Given the potentially long gap between the first divergence of the lineage and the appearance of the crown group (Tang et al., 2019), it is precisely for such a group that early diverging stem groups would be of considerable value in resolving relationships and documenting the appearance of apomorphies within the clade. Extensive study of Early Cretaceous and Jurassic deposits for stem-group Stephanidae is necessary in order to provide direct evidence into the early evolution of this critical family of the Euhymenoptera.

The first fossil Nemopteridae from the Oligocene of Céreste (France) (Insecta: Neuroptera)

Nemopteridae are a small family of myrmeleontoid lacewings characterized by elongated ribbon- or thread-like hindwings. Extant Nemopteridae comprise two subfamilies, viz. Crocinae (thread-wings) and Nemopterinae (spoon- and ribbon-wings). They are distributed in all zoogeographical regions except the Nearctic region in the extant fauna. However, the major species diversity of Nemopteridae is confined to the southern part of Africa. The fossil record of the family is scarce, with five Lower Cretaceous fossils, one from the lowermost Cenomanian, two fossils from the Upper Eocene, and two from the Oligocene (Lu et al., 2019; Nel & Jarzembowski, 2019). Here we describe a new, nearly complete fossil from the Oligocene of Lubéron in France. It was found in the Konservat Lagerstätte of Céreste, in finely laminated lacustrine limestones. It is the only specimen of this family found in this outcrop, among more than 30000 fossil insects. Neuroptera are extremely rare in this outcrop; only one adult Ascalaphidae (Ascaloptynx oligocenicus Nel, 1991) and two Mantispidae (Prosagittalata oligocenica Nel, 1988 and an undescribed specimen) have been discovered there (Nel, 1988, 1991).