''Montrichardia aquatica'' 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 ...

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 ...

monocot Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon. They constitute one of ...

plant Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...

in the family

Araceae The Araceae are a family of monocotyledonous flowering plants in which flowers are borne on a type of inflorescence called a spadix. The spadix is usually accompanied by, and sometimes partially enclosed in, a spathe (or leaf-like bract). Also ...

. ''M. aquatica'' is related to the living species '' M. arborescens'' and '' M. linifera''. The species is solely known from the Middle to Late Paleocene (about 60 to 58 Ma), fossil-rich

Cerrejón Formation The Cerrejón Formation is a geologic formation in Colombia dating back to the Middle-Late Paleocene. It is found in the El Cerrejón sub-basin of the Cesar-Ranchería Basin of La Guajira and Cesar. The formation consists of bituminous coal field ...

La Guajira La Guajira () is a department of Colombia. It occupies most of the Guajira Peninsula in the northeast region of the country, on the Caribbean Sea and bordering Venezuela, at the northernmost tip of South America. The capital city of the departm ...

, northern

Colombia Colombia (, ; ), officially the Republic of Colombia, is a country in South America with insular regions in North America—near Nicaragua's Caribbean coast—as well as in the Pacific Ocean. The Colombian mainland is bordered by the Car ...

.Cerrejón 0322
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...

.org

History and classification

The species is known only 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 ING-0904, and the four paratypes ING-0808, ING-0903, ING-0905 and ING-0906. The

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are currently residing in the collections housed by the Colombian Geological Institute in

Bogotá Bogotá (, also , , ), officially Bogotá, Distrito Capital, abbreviated Bogotá, D.C., and formerly known as Santa Fe de Bogotá (; ) during the Spanish period and between 1991 and 2000, is the capital city of Colombia, and one of the larges ...

. All five fossil specimens were collected from

exposures in the Cerrejón coal mine, located in the Rancheria Basin, Colombia. They were first studied by a group of researchers from

Florida Museum of Natural History The Florida Museum of Natural History (FLMNH) is Florida's official state-sponsored and chartered natural-history museum. Its main facilities are located at 3215 Hull Road on the campus of the University of Florida in Gainesville. The main pub ...

, the

Smithsonian Museum of Natural History The National Museum of Natural History is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. It has free admission and is open 364 days a year. In 2021, with 7. ...

and led by Fabiany Herrera from the

Smithsonian Tropical Research Institute The Smithsonian Tropical Research Institute (STRI, es, Instituto Smithsonian de Investigaciones Tropicales) is located in Panama and is the only bureau of the Smithsonian Institution based outside of the United States. It is dedicated to understa ...

. Herrera and associates published their 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 ''

American Journal of Botany The ''American Journal of Botany'' is a monthly peer-reviewed scientific journal which covers all aspects of plant biology. It has been published by the Botanical Society of America since 1914. The journal has an impact factor of 3.038, as of 201 ...

''. The specific epithet "''aquatica''", a derivation of the

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

"aquaticus", was chosen by the authors in reference to the species having lived near to, or in water.

Description

There are two

angiosperm Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...

families,

Nymphaeaceae Nymphaeaceae () is a family of flowering plants, commonly called water lilies. They live as rhizomatous aquatic herbs in temperate and tropical climates around the world. The family contains nine genera with about 70 known species. Water li ...

and

Nelumbonaceae Nelumbonaceae is a family of aquatic flowering plants. ''Nelumbo'' is the sole extant genus, containing ''Nelumbo lutea'', native to North America, and ''Nelumbo nucifera'', widespread in Asia. At least four other genera, ''Nelumbites'', ''Exne ...

which have leaf shapes very similar to ''Montrichardia aquatica''. Though the overall shape of leaves in those families may be similar the vein structure in ''M. aquatica'' is notably distinct from both. Neither family possesses the collective veins along the margin, naked secondary veins along the basal margin, and the distinct higher vein structure that is present in the fossil specimens of ''M. aquatica''. This combination of features is found within the family Araceae. ''M. aquatica'' is placed within the living Araceae genus ''

Montrichardia ''Montrichardia'' is a genus of flowering plants in the family Araceae. It contains two species, ''Montrichardia arborescens'' and '' Montrichardia linifera'', and one extinct species '' Montrichardia aquatica''. The genus is helophytic and distr ...

'' due to the unique combination of leaf morphology characters present in the fossils. Though the fossils are generally similar to the fossil genus '' Caladiosoma'' the vein structure is very dissimilar and thus is not considered a close relation. Overall, the species possesses entire margined leaves with a generally ovate shape. The leaf apex is short and rounded, while the base is heart to arrowhead shaped. Each of the basal lobes is supplied by a secondary vein which forms part of the margin and forks several times. The overall size of the leaves reached up to . Several depositional environments, at an estimated

paleolatitude Paleomagnetism (or palaeomagnetismsee ), is the study of magnetic fields recorded in rocks, sediment, or archeological materials. Geophysicists who specialize in paleomagnetism are called ''paleomagnetists.'' Certain magnetic minerals in rock ...

of 5 degrees North, appeared to have hosted ''M. aquatica''. The holotype specimen was recovered from a

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

that probably was an overbank deposits of a

fluvial In geography and geology, fluvial processes are associated with rivers and streams and the deposits and landforms created by them. When the stream or rivers are associated with glaciers, ice sheets, or ice caps, the term glaciofluvial or fluviog ...

environment. The paratype specimens were recovered from gray

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, p ...

s underlying one of the thickest coal sequences in the Cerrejón Formation. These layers are most likely from a swampy to lake like environment.

References

{{Taxonbar, from=Q15295626 Aroideae Paleogene life of South America Itaboraian Peligran Prehistoric plants of South America Flora of Colombia Fossils of Colombia Paleogene Colombia Cerrejón Formation Fossil taxa described in 2008