ELLIOTT ET AL.: THE CAVE FAUNA OF CALIFORNIA 
3 
A troglobite is an animal that is limited to caves and similar habitats, and exhibits troglomor- 
phy; also known as a “troglobiont,” obligate cavemicole, or obligate subterranean species. A sty- 
gobite (stygobiont) is an aquatic troglobite. Troglomorphy includes the physical characteristics of 
a troglobite or stygobite; e.g., reduced eyes and pigment, elongated appendages, well-developed 
tactile and olfactory organs, etc. See Appendix 3, Glossary, for definitions of biological and geo¬ 
logical terms. 
At least 1,366 taxa are recorded in subterranean habitats in California (Appendix 1), including 
102 terrestrial troglobites (terrestrial troglobionts), 12 stygobites (aquatic troglobionts), and 32 
phreatobites (obligate, usually troglomorphic groundwater forms), a total of 146 obligate subter¬ 
ranean taxa. Half (72) of the subterranean obligates are considered by taxonomists to be new (cur¬ 
rently undescribed) species, with 61 troglobites, 3 stygobites, and 8 phreatobites. Our species list 
includes 109 new (undescribed) species of all types, significantly adding to our knowledge of Cal¬ 
ifornia’s biodiversity. 
The number of species known from California caves will doubtless increase dramatically as 
more caves, especially in remote areas, are studied. In addition, many collections, especially of 
mites, spiders, centipedes, collembolans, flies, and other insect groups, await taxonomic study. 
Geology and Cave Regions 
Geologic Setting 
California is a large state (1,345 km by 350 km, 423,970 km 2 ) with complex physiography and 
geology; it contains a diverse array of karst (carbonate rocks), volcanic, littoral (sea), and other 
cave types (Fig. 1). Along with 450 defined aquifers (Carle 2004), there are numerous subterranean 
habitats in which animals survive and adapt. In addition, more than 39,000 inactive mines occur in 
many rock types across the state (California Department of Conservation 2000). 
The state is a mosaic of plutonic, volcanic, metamorphic, and sedimentary rocks, often close¬ 
ly juxtaposed. Karst areas in California are formed in ancient carbonate terranes that originated as 
reef islands in the Paleo-Pacific Ocean, and were rafted on the ancient Farallon plate until they 
accreted onto the west coast of North America along with other terranes. The Farallon plate col¬ 
lided with the North American plate and was largely subducted beneath it. The remains of the Far¬ 
allon plate are the Juan de Fuca, Explorer and Gorda plates (Lonsdale 2005). 
The oldest carbonates are from the late Paleozoic Era, Carboniferous age, about 300 Ma (mil¬ 
lion years ago). A major karst formation, the Calaveras Assemblage, contains sparse fossils of Per¬ 
mian age (299 to 252 Ma) in its upper part, and it is strung out in many outcrops along the west 
flank of the Sierra. Marble Mountain, part of the Klamath Mountains in the north, also is of Per¬ 
mian age. Later carbonates are from the Mesozoic Era, probably Triassic age, 250-200 Ma. These 
terranes underwent deep burial and metamorphism, and some became “roof pendants” embedded 
in the Sierra Nevada Batholith. 
The Sierra Nevada is 600 km long and 60 to 120 km wide. The Sierra Nevada Batholith is the 
core of the Sierra, a large mass of igneous intrusive (plutonic) rock that formed during the late 
Triassic (~210Ma) into the late Cretaceous (~ 80 Ma). The batholith formed from 
cooled magma deep in the Earth’s crust. The batholith is composed of many individual plutons, 
which formed deep underground during separate episodes of magma intrusion, long before the 
Sierra itself first began to rise (Bateman 1988). 
Two major episodes of uplift and tilting ensued in the late Mesozoic, 120-80 Ma, followed by 
erosion. A second episode in the late Cenozoic, 10-3 Ma, caused uplift in the form of westward tilt¬ 
ing of the range as a block. Exhumation of the carbonates and subsequent karstification followed 
