''Allocordyceps'' is an extinct genus of

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The ent ...

fungus A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

in the order

Hypocreales The Hypocreales are an order of fungi within the class Sordariomycetes. In 2008, it was estimated that it contained some 237 genera, and 2647 species in seven families. Since then, a considerable number of further taxa have been identified, in ...

that parasitized

carpenter ant Carpenter ants (''Camponotus'' spp.) are a genus of large ants (workers ) indigenous to many parts of the world. True carpenter ants build nests inside wood, consisting of galleries chewed out with their mandibles or jaws, preferably in dead, ...

s. The fossil of ''Allocordyceps baltica'', from the

Baltic Amber Baltic amber or succinite is amber from the Baltic region, home of its largest known deposits. It was produced sometime during the Eocene epoch, but exactly when is controversial. It has been estimated that this forested region provided the re ...

, represents the oldest known

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

of an

ant Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Cre ...

-parasitizing

before '' Ophiocordyceps''. Carpenter Ant Camponotus novaeboracensis workers

Description

''Allocordyceps'' is characterized by its ascoma being an orange color, stalked and cusp shaped. It also has a pair of partially immersed

perithecia An ascocarp, or ascoma (: ascomata), is the fruiting body ( sporocarp) of an ascomycete phylum fungus. It consists of very tightly interwoven hyphae and millions of embedded asci, each of which typically contains four to eight ascospores. Ascoc ...

that emerges from the

rectum The rectum (: rectums or recta) is the final straight portion of the large intestine in humans and some other mammals, and the gut in others. Before expulsion through the anus or cloaca, the rectum stores the feces temporarily. The adult ...

. Hosts parasitized by ''Allocordyceps'' have separate

stromata The ''Stromata'' (), a mistake for ''Stromateis'' (Στρωματεῖς, "Patchwork," i.e., ''Miscellanies''), attributed to Clement of Alexandria (c. 150 – c. 215), is the third of a trilogy of works regarding the Christian life. The oldest ...

with separate

mycelium Mycelium (: mycelia) is a root-like structure of a fungus consisting of a mass of branching, thread-like hyphae. Its normal form is that of branched, slender, entangled, anastomosing, hyaline threads. Fungal colonies composed of mycelium are fo ...

emerging from the neck and abdomen. It may have altered its host's behavior similarly to the extant ''

Ophiocordyceps unilateralis ''Ophiocordyceps unilateralis'', commonly known as zombie-ant fungus, is an entomopathogenic fungus, insect-pathogenic fungus, discovered by the British naturalist Alfred Russel Wallace in 1859. Zombie ants, infected by the ''Ophiocordyceps unila ...

''.

References

Clavicipitaceae Hypocreales genera Monotypic Ascomycota genera Paleogene fungi Parasitic fungi Taxa described in 2021 Taxa named by George Poinar Jr. {{Fungus-stub