''Patagorhynchus'' is a genus of prehistoric

monotreme Monotremes () are mammals of the order Monotremata. They are the only group of living mammals that lay eggs, rather than bearing live young. The extant monotreme species are the platypus and the four species of echidnas. Monotremes are typified ...

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

from the Late

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

(early

Maastrichtian The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...

)

Chorrillo Formation The Chorrillo Formation, also named as Chorillo Formation,Río Leona
at Fossilworks.org is ...

of Santa Cruz Province,

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

. The genus contains a single species, ''Patagorhynchus pascuali''. The

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

, MPM-PV-23087, consists of a lower right molar attached to a fragment of the

dentary In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone ...

. Based on comparisons with the closely related '' Obdurodon'', it is estimated to have weighed ~1.58 kg. It was collected near Rio Gallegos, Santa Cruz, Argentina in 2022 and is housed in the Museo Padre Molina.

Etymology

The first part of the

genus name Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial spec ...

, ''Patago'', refers to

Patagonia Patagonia () is a geographical region that includes parts of Argentina and Chile at the southern end of South America. The region includes the southern section of the Andes mountain chain with lakes, fjords, temperate rainforests, and glaciers ...

and

Ancient Greek Ancient Greek (, ; ) includes the forms of the Greek language used in ancient Greece and the classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

ῥύγχος (''rhúnkhos''), meaning "snout". The species name ''pascuali'' honors Argentine paleomammalogist Rosendo Pascual.

Evolution

''Patagorynchus'' represents the oldest known monotreme species from South America, indicating that they had already arrived in the region by the end of the Cretaceous, and were present in Antarctica during the Late Cretaceous.

Classification

Chimento ''et al''. (2023) recovered ''Patagorhynchus'' as a monotreme mammal. The simplified results of their

phylogenetic analyses In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as Computational phylogenetics, phylogenetic inference. It infers the relationship among organ ...

are shown in the

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

below:

References

{{Taxonbar, from1=Q117089757, from2=Q124310671 Fossil taxa described in 2023 Prehistoric monotremes Late Cretaceous mammals of South America Prehistoric mammal genera Cretaceous Argentina Fossils of Argentina