''Paleoleishmania'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

kinetoplastids Kinetoplastida (or Kinetoplastea, as a class) is a group of flagellated protists belonging to the phylum Euglenozoa, and characterised by the presence of an organelle with a large massed DNA called kinetoplast (hence the name). The organisms are ...

, a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

group of unicellular parasitic

flagellate A flagellate is a cell or organism with one or more whip-like appendages called flagella. The word ''flagellate'' also describes a particular construction (or level of organization) characteristic of many prokaryotes and eukaryotes and their ...

protozoa Protozoa (singular: protozoan or protozoon; alternative plural: protozoans) are a group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic tissues and debris. Histo ...

. At present it is placed in the family Trypanosomatidae. The genus contains two

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

, ''Paleoleishmania neotropicum'' and the type species ''Paleoleishmania proterus''. The genus is known from the Albian aged Burmese amber deposits of northern

Myanmar Myanmar, ; UK pronunciations: US pronunciations incl. . Note: Wikipedia's IPA conventions require indicating /r/ even in British English although only some British English speakers pronounce r at the end of syllables. As John C. Wells, Joh ...

and the

Burdigalian The Burdigalian is, in the geologic timescale, an age (geology), age or stage (stratigraphy), stage in the early Miocene. It spans the time between 20.43 ± 0.05 annum, Ma and 15.97 ± 0.05 Ma (million years ago). Preceded by the Aquitanian (sta ...

aged

Dominican amber Dominican amber is amber from the Dominican Republic derived from resin of the extinct tree ''Hymenaea protera''. Dominican amber differentiates itself from Baltic amber by being nearly always transparent, and it has a higher number of fossil incl ...

deposits on the island of

Hispaniola Hispaniola (, also ; es, La Española; Latin and french: Hispaniola; ht, Ispayola; tnq, Ayiti or Quisqueya) is an island in the Caribbean that is part of the Greater Antilles. Hispaniola is the most populous island in the West Indies, and th ...

Etymology

The genus name ''Paleoleishmania'' is derived from the Greek ''paleo'' meaning "old" and ''leishmania'' referencing the modern

Leishmaniasis Leishmaniasis is a wide array of clinical manifestations caused by parasites of the trypanosome genus ''Leishmania''. It is generally spread through the bite of phlebotomine sandflies, ''Phlebotomus'' and ''Lutzomyia'', and occurs most freq ...

-causing genus ''

Leishmania ''Leishmania'' is a parasitic protozoan, a single-celled organism of the genus '' Leishmania'' that are responsible for the disease leishmaniasis. They are spread by sandflies of the genus ''Phlebotomus'' in the Old World, and of the genus '' ...

''. All trypanosomes are heteroxenous (requiring more than one obligatory host in order to complete life cycle) or are transmitted through some variation of a vector.

''Paleoleishmania proterus''

The genus was described in 2004 by

George Poinar Jr. George O. Poinar Jr. (born April 25, 1936) is an American entomologist and writer. He is known for popularizing the idea of extracting DNA from insects fossilized in amber, an idea which received widespread attention when adapted by Michael Cr ...

and Robert Poinar in the journal ''

Protist A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the exc ...

'' from

amastigotes An amastigote is a protist A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryot ...

, promastigotes and paramastigotes preserved with a blood engorged female '' Palaeomyia burmitis'' sandfly preserved in Burmese amber. The species was named ''Paleoleishmania proterus'' and the genus was erected for fossil digenetic

trypanosomes Trypanosomatida is a group of kinetoplastid excavates distinguished by having only a single flagellum. The name is derived from the Greek ''trypano'' (borer) and ''soma'' (body) because of the corkscrew-like motion of some trypanosomatid species. ...

. ''P. proterus'' was the first

kinetoplastid Kinetoplastida (or Kinetoplastea, as a class) is a group of flagellated protists belonging to the phylum Euglenozoa, and characterised by the presence of an organelle with a large massed DNA called kinetoplast (hence the name). The organisms are ...

to be described from the fossil record.

''Paleoleishmania neotropicum''

''Paleoleishmania neotropicum'' is known solely from the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

specimen, number # P-3–5, amastigotes and paramastigotes associated with the species host, a relatively complete female sandfly of the species '' Lutzomyia adiketis''. ''P. neotropicum'' and ''L. adiketis'' are preserved in a polished piece of amber and thick. The amber specimen is currently residing in the Poinar Amber Collection housed at the

Oregon State University Oregon State University (OSU) is a public land-grant, research university in Corvallis, Oregon. OSU offers more than 200 undergraduate-degree programs along with a variety of graduate and doctoral degrees. It has the 10th largest engineering co ...

Corvallis, Oregon Corvallis ( ) is a city and the county seat of Benton County in central western Oregon, United States. It is the principal city of the Corvallis, Oregon Metropolitan Statistical Area, which encompasses all of Benton County. As of the 2020 United ...

. Poinar published his 2008

type description A species description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species that have be ...

in the journal ''

Parasites & Vectors ''Parasites & Vectors'' is a peer-reviewed open-access medical journal published by BioMed Central. The journal publishes articles on the biology of parasites, parasitic diseases, intermediate hosts, vectors and vector-borne pathogens. ''Parasites ...

''. During the fly's struggle to escape from the resin, the alimentary tract was ruptured and some ''P. neotropicum'' flagellates leaked from there into the

hemocoel The blood circulatory system is a organ system, system of organs that includes the heart, blood vessels, and blood which is circulated throughout the entire body of a human or other vertebrate. It includes the cardiovascular system, or vascula ...

. ''P. neotropicum'' and ''L. adiketis'' lived in an environment similar to modern moist tropical rain forests. The morphology of the compact

kinetoplast A kinetoplast is a network of circular DNA (called kDNA) inside a large mitochondrion that contains many copies of the mitochondrial genome. The most common kinetoplast structure is a disk, but they have been observed in other arrangements. Kinet ...

nucleus Nucleus ( : nuclei) is a Latin word for the seed inside a fruit. It most often refers to: *Atomic nucleus, the very dense central region of an atom *Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA Nucle ...

, and rear-facing

flagellum A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have f ...

indicate the species belongs in the family Trypanosomatidae. The preserved amastigotes are between 4 and 7

µm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

and their presence in the fly indicates the digenetic nature of the species. That the species is digenetic excludes the ''

Blastocrithidia ''Blastocrithidia'' is a genus of parasitic flagellate protist belonging to the family Trypanosomatidae. It is a monoxenous parasite of heteropteran insects, mainly inhabiting their hindgut and glands. Characteristics In addition to ''Blast ...

'' as a possible genus placement for the species, while '' Endotrypanum'' is specific to sloths which are not known on Hispaniola past the

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ...

. The genus ''

Phytomonas ''Phytomonas'' is a genus of trypanosomatids that infect plant species. Initially described using existing genera in the family Trypanosomatidae, such as ''Trypanosoma'' or ''Leishmania'', the nomenclature of ''Phytomonas'' was proposed in 1909 ...

'' is excluded due to it being exclusively found in hemipterans. The paramastigotes range in size from 6 to 10 µm which is within the range for modern ''Leishmania'' species. There are several possible origins for the paramastigotes preserved in the proboscis. They probably developed within the proboscis from an earlier meal of the fly, however they may have been "infective promastigotes" which occur naturally in the mouthparts of some ''Lutzomyia'' species. Though they are currently placed in the same genus, Dr. Poinar notes the likelihood that the two species arose interdependently from each other. It is possible ''P. neotropicum'' is the ancestor of one or more Neotropical ''Leishmania'' clades.

References

{{Taxonbar, from=Q21445997 Trypanosomatida Euglenozoa genera Albian genus first appearances Burdigalian extinctions Burmese amber Fossils of the Dominican Republic Dominican amber Fossil taxa described in 2004 Taxa named by George Poinar Jr.