Paeromopodidae is a

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

of large cylindrical

millipede Millipedes (originating from the Latin , "thousand", and , "foot") are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments; they are known scientifically as the class Diplopoda, the name derive ...

s of the order

Julida Julida is an order of millipedes. Members are mostly small and cylindrical, typically ranging from in length. Eyes may be present or absent, and in mature males of many species, the first pair of legs is modified into hook-like structures. Addit ...

native to the western United States of America. The family contains two genera and ten species and includes the longest millipedes in North America, with individuals reaching up to long.

Description

Paeromopodids possess 60 to 80 body segments and range from long and 2 to 8 mm wide as adults. Paeromopodids have distinct parallel grooves called ''striae'' on their body rings that give a somewhat roughened texture and distinguishes them from other cylindrical western millipedes. Individuals may be rather uniformly blue gray, or colored in alternating bands of light and dark brown, or may possess a dorsal lengthwise stripe of yellow or light brown.

Distribution

Paeromopodids are endemic to the United States and occur in two distinct areas: the first is a large Pacific coast range extending from

Washington state Washington, officially the State of Washington, is a state in the Pacific Northwest region of the United States. It is often referred to as Washington State to distinguish it from the national capital, both named after George Washington ...

to the southern

Sierra Nevada The Sierra Nevada ( ) is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primari ...

and

Death Valley Death Valley is a desert valley in Eastern California, in the northern Mojave Desert, bordering the Great Basin Desert. It is thought to be the Highest temperature recorded on Earth, hottest place on Earth during summer. Death Valley's Badwat ...

region of

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

and east to the

Warner Mountains The Warner Mountains are an -long mountain range running north–south through northeastern California and extending into southern Oregon in the United States. The range lies within the northwestern corner of the Basin and Range Province, ext ...

straddling the borders of California,

Oregon Oregon ( , ) is a U.S. state, state in the Pacific Northwest region of the United States. It is a part of the Western U.S., with the Columbia River delineating much of Oregon's northern boundary with Washington (state), Washington, while t ...

, and

Nevada Nevada ( ; ) is a landlocked state in the Western United States. It borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the seventh-most extensive, th ...

; and the second is a region spanning extreme northeastern Oregon, across the

Idaho Panhandle The Idaho panhandle—locally known as North Idaho, Northern Idaho, or simply the Panhandle—is a salient region of the U.S. state of Idaho encompassing the state's 10 northernmost counties: Benewah, Bonner, Boundary, Clearwater, Idaho, ...

to western

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

. Species of '' Paeromopus'' are generally larger than '' Californiulus'', and occur only in California. Species of ''Californiulus'' occur in California as well as the rest of the range of the family.

Ecology and behavior

Paeromopodids are relatively active and fast-moving millipedes, with a high degree of flexibility. Many species are found under rocks or moist, rotten logs as opposed to buried in

leaf litter Plant litter (also leaf litter, tree litter, soil litter, litterfall, or duff) is dead plant material (such as leaves, bark, needles, twigs, and cladodes) that has fallen to the ground. This detritus or dead organic material and its constituen ...

, and species of ''Californiulus'' may prefer drier microhabitats than ''Paeromopus''. ''C. blechrostriatus'' inhabits the arid eastern slopes of the Sierra into Death Valley, and has been found at elevations of up to 2,400 m (8,000 ft).

Species

Genus '' Californiulus'' *'' Californiulus blechrostriatus'' *'' Californiulus chamberlini'' *'' Californiulus dorsovittatus'' *'' Californiulus euphanus'' *'' Californiulus parvior'' *'' Californiulus yosemitensis'' Genus '' Paeromopus'' *'' Paeromopus angusticeps'' *'' Paeromopus cavicolens'' *'' Paeromopus eldoradus'' *'' Paeromopus paniculus''

References

{{Taxonbar, from=Q4283681 Julida Millipedes of North America Endemic fauna of the United States Fauna of the Western United States Millipede families