George Poinar

The oldest fossil evidence of animal parasitism by fungi supports a Cretaceous diversification of fungal-arthropod symbioses

Paleoophiocordyceps coccophagus, a fungal parasite of a scale insect from the Early Cretaceous (Upper Albian), is reported and described here. This fossil not only provides the oldest fossil evidence of animal parasitism by fungi but also contains morphological features similar to asexual states of Hirsutella and Hymenostilbe of the extant genus Ophiocordyceps (Ophiocordycipitaceae, Hypocreales, Sordariomycetes, Pezizomycotina, Ascomycota). Because species of Hypocreales collectively exhibit a broad range of nutritional modes and symbioses involving plants, animals and other fungi, we conducted ancestral host reconstruction coupled with phylogenetic dating analyses calibrated with P.coccophagus. These results support a plant-based ancestral nutritional mode for Hypocreales, which then diversified ecologically through a dynamic process of intra- and interkingdom host shifts involving fungal, higher plant and animal hosts. This is especially evident in the families Cordycipitaceae, Clavicipitaceae and Ophiocordycipitaceae, which are characterized by a high occurrence of insect pathogens. The ancestral ecologies of Clavicipitaceae and Ophiocordycipitaceae are inferred to be animal pathogens, a trait inherited from a common ancestor, whereas the ancestral host affiliation of Cordycipitaceae was not resolved. Phylogenetic dating supports both a Jurassic origin of fungal-animal symbioses within Hypocreales and parallel diversification of all three insect pathogenic families during the Cretaceous, concurrent with the diversification of insects and angiosperms.

Parasite‐Induced Fruit Mimicry in a Tropical Canopy Ant

Some parasites modify characteristics of intermediate hosts to facilitate their consumption by subsequent hosts, but examples of parasite‐mediated mimicry are rare. Here we report dramatic changes in the appearance and behavior of nematode‐parasitized ants such that they resemble ripe fruits in the tropical rain forest canopy. Unlike healthy ants, which are completely black, infected ants have bright red, berry‐like gasters full of parasite eggs. The infected gasters are held in a conspicuous elevated position as the ants are walking, and they are easily detached from living ants, which also exhibit reduced defensive responses. This combination of changes presumably makes the infected ants attractive to frugivorous birds, which ingest the red gasters and pass the parasite eggs in their feces. The feces are collected by ants and fed to the developing brood, thus completing the cycle. This is the first documentation of parasites causing apparent fruit mimicry in an animal host to complete their life cycle.

A new species of resinicolous Chaenothecopsis (Mycocaliciaceae, Ascomycota) from 20 million year old Bitterfeld amber, with remarks on the biology of resinicolous fungi

Chaenothecopsis bitterfeldensis sp. nov. is described and illustrated from Bitterfeld amber dating back to at least 20 million years ago. There has been no previous report of the sporing perfect stage of any Ascomycota in amber. The fungus also represents the first fossil record of resinicolous fungi and of the Mycocaliciaceae. The fossilised specimen contains over 20 fruiting bodies arising from an extensive mycelium. There are also hundreds of detached ascospores, some of which had germinated before the resin was transformed into amber. The taxonomy and palaeontology of the fossil fungus is discussed and stages in its preservation are described. Also some general aspects in the biology of resinicolous Mycocaliciaceae are reviewed. The striking similarity of C. bitterfeldensis to some extant species from East Asia suggests that the present distribution of these fungi is a relict of an ancient Laurasian range.

Paleoleishmania proterus n. gen., n. sp., (Trypanosomatidae: Kinetoplastida) from Cretaceous Burmese amber.

A trypanosomatid (Trypanosomatidae: Kinetoplastida) associated with a blood-filled female sand fly in Cretaceous Burmese amber, is described in the new genus and species, Paleoleishmania proterus. The genus Paleoleishmania is established as a collective genus for digenetic fossil trypanosomes associated with sand flies. Amastigotes, promastigotes and paramastigotes are described. Paleoleishmania proterus is the first fossil kinetoplastid and provides a minimum age for the digenetic Trypanosomatidae. Its discovery indicates that vector-borne pathogens had been established by the Early Cretaceous.

Tapeworm Eggs in a 270 Million-Year-Old Shark Coprolite

Remains of parasites in vertebrates are rare from the Mesozoic and Paleozoic. Once most parasites that live in – or pass through – the gastrointestinal tract of vertebrates, fossil feces (coprolites) or even intestinal contents (enterolites) can eventually preserve their remains. Here we announce the discovery of a spiral shark coprolite from the Paleozoic bearing a cluster of 93 small oval-elliptical smooth-shelled structures, interpreted as eggs of a tapeworm.The eggs were found in a thin section of an elasmobranch coprolite. Most of the eggs are filled by pyrite and some have a special polar swelling (operculum), suggesting they are non-erupted eggs. One of the eggs contains a probable developing larva. The eggs are approximately 145–155 µm in length and 88–100 µm in width and vary little in size within the cluster. The depositional and morphological features of the eggs closely resemble those of cestodes. Not only do the individual eggs have features of extant tapeworms, but their deposition all together in an elongate segment is typical to modern tapeworm eggs deposited in mature segments (proglottids). This is the earliest fossil record of tapeworm parasitism of vertebrates and establishes a timeline for the evolution of cestodes. This discovery shows that the fossil record of vertebrate intestinal parasites is much older than was hitherto known and that the interaction between tapeworms and vertebrates occurred at least since the Middle-Late Permian.

Plasmodium dominicana n. sp. (Plasmodiidae: Haemospororida) from Tertiary Dominican amber

Plasmodium dominicana n. sp. is described from Tertiary Dominican Republic amber. The description is based on oöcysts, sporozoites and possible microgametes and an ookinete in the body-cavity of a female Culex mosquito (Diptera: Culicidae: Culicinae). The large pedunculated oöcysts, together with the culicine vector, align the fossil with the extant avain malaria species, P. juxtanucleare Versiani & Gomes, 1941. Based on the host range of P. juxtanucleare, a possible primary host would have been a member of the order Galliformes. This discovery establishes a minimum age for the genus Plasmodium Marchiafava & Celli, 1885 and places avian malaria in the Americas by the mid-Tertiary. It also supports earlier theories that some species of primate malaria could have evolved in the Americas.

Fossilised Anzia (Lecanorales, lichen-forming Ascomycota) from European Tertiary amber

Anzia electra sp. nov. is described and illustrated from Baltic amber dating back approx. 40 Myr. The diagnostic features of the fossilised species include the small, narrow lobed foliose thallus, two-layered medulla, lack of chondroidal axis, moniliform spongiostratum, and rhizines born singly at the margins of spongiostratum cushions. The fossil species demonstrates that all distinguishing features in the thallus morphology of Anzia sect. Anzia have remained stable for tens of millions of years. Hence the divergence of anzioid lichens must have occurred in the distant past, most probably before the Tertiary. The fossil also provides the first hard evidence that the disjunct-Laurasian distributions of some modern lichens represent relicts of a formerly wider range. The close similarity of the fossil to extant species in East Asia and eastern North America suggests that the present range of Anzia sect. Anzia is highly relict.

A new species of Phyllopsora (Lecanorales, lichen-forming Ascomycota) from Dominican amber, with remarks on the fossil history of lichens

Phyllopsora dominicanus sp. nov. (Bacidiaceae, Lecanorales, lichen-forming Ascomycota) is described and illustrated from Dominican amber. The diagnostic features of the lichen include a minute subfolious thallus of lacinulate, ascending squamules, a well-developed upper cortex, and a net-like pseudocortex on the lower surface. The algal symbionts are unicellular green algae, forming a distinct layer immediately below the upper cortex. The fossil demonstrates that distinguishing features of Phyllopsora have remained unchanged for tens of millions of years. The fossil also provides the first detailed views of mycobiont-photobiont contacts in Tertiary green algal lichens. The mycobiont hyphae formed apical and intercalary appressoria by pressing closely against the photobiont cells. This indicates that a conserved maintenance of structure is also seen in the fine details of the fungal-algal interface.

Palaeonema phyticum gen. n., sp. n. (Nematoda: Palaeonematidae fam. n.), a Devonian nematode associated with early land plants

Nematodes are one of the most abundant groups of invertebrates on the face of the earth. Their extremely poor fossil record hinders our ability to assess just when members of this group invaded land and first became associated with plants. This study reports fossil nematodes from the stomatal chambers of the Early Devonian (396 mya) land plant, Aglaophyton major. These nematodes, which are tentatively assigned to the order Enoplia, are described as Palaeonema phyticum gen. n., sp. n. in the new family Palaeonematidae fam. n. Diagnostic characters of the family are: i) cuticular striations; ii) uniform, cylindrical pharynx with the terminal portion only slightly set off from the remainder; and iii) a two-portioned buccal cavity with the upper portion bearing protuberances. The presence of eggs, juveniles and adults in family clusters within the plant tissues provide the earliest evidence of an association between terrestrial plants and animals and may represent an early stage in the evolution of plant parasitism by nematodes.

Description of an early Cretaceous termite (Isoptera: Kalotermitidae) and its associated intestinal protozoa, with comments on their co-evolution

BackgroundThe remarkable mutualistic associations between termites and protists are in large part responsible for the evolutionary success of these eusocial insects. It is unknown when this symbiosis was first established, but the present study shows that fossil termite protists existed in the Mesozoic.ResultsA new species of termite (Kalotermes burmensis n. sp.) in Early Cretaceous Burmese amber had part of its abdomen damaged, thus exposing trophic stages and cysts of diverse protists. Some protists were still attached to the gut intima while others were in the amber matrix adjacent to the damaged portion. Ten new fossil flagellate species in the Trichomonada, Hypermastigida and Oxymonadea are described in nine new genera assigned to 6 extant families. Systematic placement and names of the fossil flagellates are based on morphological similarities with extant genera associated with lower termites. The following new flagellate taxa are established: Foainites icelus n. gen. n. sp., Spiromastigites acanthodes n. gen. n. sp., Trichonymphites henis n. gen., n. sp., Teranymphites rhabdotis n. gen. n. sp., Oxymonas protus n. sp., Oxymonites gerus n. gen., n. sp., Microrhopalodites polynucleatis n. gen., n. sp., Sauromonites katatonis n. gen., n. sp., Dinenymphites spiris n. gen., n. sp., Pyrsonymphites cordylinis n. gen., n. sp. A new genus of fossil amoeba is also described as Endamoebites proterus n. gen., n. sp. Fourteen additional trophic and encystid protist stages are figured and briefly characterized.ConclusionThis represents the earliest fossil record of mutualism between microorganisms and animals and the first descriptions of protists from a fossil termite. Discovering the same orders, families and possibly genera of protists that occur today in Early Cretaceous kalotermitids shows considerable behaviour and morphological stability of both host and protists. The possible significance of protist cysts associated with the fossil termite is discussed in regards the possibility that coprophagy, as well as proctodeal trophallaxis, was a method by which some termite protozoa were transferred intrastadially and intergenerationally at this time.