''Schendylops ramirezi'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

of soil centipede in the family

Schendylidae Schendylidae is a family of Geophilomorpha, soil centipedes in the superfamily Himantarioidea and the order Geophilomorpha. These centipedes are found in the Americas, the Palearctic realm, Palearctic region, Africa, Madagascar, Australia, and ...

. This

centipede Centipedes (from Neo-Latin , "hundred", and Latin , "foot") are predatory arthropods belonging to the class Chilopoda (Ancient Greek , ''kheilos'', "lip", and Neo-Latin suffix , "foot", describing the forcipules) of the subphylum Myriapoda, ...

is notable as the species with the fewest legs recorded in the order

Geophilomorpha Geophilomorpha is an order of centipedes commonly known as soil centipedes. The name "Geophilomorpha" is from Ancient Greek roots meaning "formed to love the earth." This group is the most diverse centipede order, with 230 genera. These centiped ...

for each sex (27 pairs of legs for males, 29 leg pairs for females). This species is also the smallest in the genus ''

Schendylops ''Schendylops'' is the largest genus of centipedes in the family Schendylidae, containing more than 60 species. This genus was first proposed by the American biologist Orator F. Cook in 1899 for the type species originally named ''Schendyla gran ...

'', reaching only in length.

Discovery

This species was first described in 2013 by the Argentine myriapodologist Luis Alberto Pereira of the

Universidad Nacional de La Plata The National University of La Plata (, UNLP) is a national public research university located in the city of La Plata, capital of Buenos Aires Province, Argentina. It has over 90,000 regular students, 10,000 teaching staff, 17 departments and 10 ...

based on specimens collected in 1999 in

Brazil Brazil, officially the Federative Republic of Brazil, is the largest country in South America. It is the world's List of countries and dependencies by area, fifth-largest country by area and the List of countries and dependencies by population ...

. These specimens include a female

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 ...

, five

paratype In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype (biology), isotype ...

s (three males and two females), and nineteen other specimens (fifteen females and four males), including five subadults and fourteen juveniles. The species is named for the Argentine

arachnologist Arachnology is the scientific study of arachnids, which comprise spiders and related invertebrates such as scorpions, pseudoscorpions, harvestmen, ticks, and mites. Those who study spiders and other arachnids are arachnologists. More narrowly ...

Martin Javier Ramirez of the Museo Argentino de Ciencias Naturales in

Buenos Aires Buenos Aires, controlled by the government of the Autonomous City of Buenos Aires, is the Capital city, capital and largest city of Argentina. It is located on the southwest of the Río de la Plata. Buenos Aires is classified as an Alpha− glob ...

, who collected all the specimens. These specimens are deposited at the Museu de Zoologia da Universidade de São Paulo.

Description

This species exhibits

sexual dimorphism Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...

in leg number: All seven male specimens have only 27 leg pairs, and all eighteen female specimens have only 29 pairs. The holotype female (preserved in alcohol) has a pale yellowish color and measures in length and in maximum body width. The two female paratypes range from in length, whereas the three male paratypes range from in length. The five subadults (two females and three males) measure in length and the fourteen juveniles (thirteen females and one male) range from in length. Given the small size of these tiny centipedes, the original description refers to ''S. ramirezi'' as a "dwarf species." Only one species of soil centipede other than ''S. ramirezi'', is known to include centipedes with only 27 pairs of legs: ''

Schendylops oligopus ''Schendylops oligopus'' is a species of soil centipede in the family Schendylidae. This species is notable as one of only two species in the order Geophilomorpha known to include centipedes with only 27 pairs of legs, the minimum number recorded ...

''. Males of the species ''S. oligopus'' have 27 or 29 leg pairs, whereas females of this species have 31 pairs. These males, however, usually have 29 leg pairs and rarely have only 27 pairs. In a large sample of 31 males, only one specimen had only 27 leg pairs. Furthermore, only one species of soil centipede other than ''S. ramirez'' is known to include females with only 29 leg pairs: '' Dinogeophilus oligopodus'', with 29 leg pairs in both sexes. Thus, only ''S. ramirezi'' features the minimum number of legs recorded in the order Geophilomorpha for males as well as for females. Only six species in the order Geophilomorpha, including ''S. ramirezi'', ''S. oligopus'', and ''D. oligopodus'', are known to feature centipedes with only 29 leg pairs. The species ''S. ramirezi'' shares a distinctive set of traits with several other species of ''Schendylops'', including ''S. oligopus''. These features include undivided pore-fields that are limited to the anterior region of the body, but without a pore-field on the

sternite The sternum (: sterna) is the ventral portion of a segment of an arthropod thorax or abdomen. In insects, the sterna are usually single, large sclerites, and external. However, they can sometimes be divided in two or more, in which case the su ...

of the first leg-bearing segment. Furthermore, in both species, the fourth segment of each antenna is similar in length to the contiguous segments. Although ''S. ramirez'' and ''S. oligopus'' share many features, including a similar number of legs, these two species also differ from one another in numerous respects. For example, whereas ''S. ramirezi'' features

seta In biology, setae (; seta ; ) are any of a number of different bristle- or hair-like structures on living organisms. Animal setae Protostomes Depending partly on their form and function, protostome setae may be called macrotrichia, chaetae, ...

e on the coxosternite of the first

maxillae In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxillar ...

and a large seta in the middle of the coxosternite of the second maxillae, all these setae are absent in ''S. oligopus''. Furthermore, while both species are small, ''S. oligopus'' is nevertheless larger than ''S. ramirezi'': Females of the species ''S. oligopus'' can reach 10 mm in length, and males can reach 8 mm in length.

Distribution

This species is known only from the type locality (

Ilha Grande Ilha Grande (), or "big island", is a forested island located around 12 km (7.5 mi) off of the Atlantic coast of Angra dos Reis, Rio de Janeiro, Brazil, and about 243 km (151 mi) from São Paulo. The highest point on Ilha Grande is the tall Pic ...

) in the

state State most commonly refers to: * State (polity), a centralized political organization that regulates law and society within a territory **Sovereign state, a sovereign polity in international law, commonly referred to as a country **Nation state, a ...

Rio de Janeiro Rio de Janeiro, or simply Rio, is the capital of the Rio de Janeiro (state), state of Rio de Janeiro. It is the List of cities in Brazil by population, second-most-populous city in Brazil (after São Paulo) and the Largest cities in the America ...

in Brazil.

References

{{Taxonbar, from=Q30916011 Schendylidae Animals described in 2013 Endemic arthropods of Brazil