Paeromopodidae is a

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

of large cylindrical

millipede Millipedes 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 derived from this feature. Each double-legged segment is a resu ...

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 Western United States. Named for George Washington—the first U.S. president—the state was formed from the western part of the 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 primarily ...

and

Death Valley Death Valley is a desert valley in Eastern California, in the northern Mojave Desert, bordering the Great Basin Desert. During summer, it is the Highest temperature recorded on Earth, hottest place on Earth. Death Valley's Badwater Basin is the ...

region of

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

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, exte ...

straddling the borders of California,

Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...

, and

Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...

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

Idaho Panhandle The Idaho Panhandle—locally known as North Idaho—is a salient region of the U.S. state of Idaho encompassing the state's 10 northernmost counties: Benewah, Bonner, Boundary, Clearwater, Idaho, Kootenai, Latah, Lewis, Nez Perce, and Shosh ...

to western

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columbi ...

. 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 have fallen to the ground. This detritus or dead organic material and its constituent ...

, 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