Main Menu   Sites

Anza-Borrego Desert State Park

CA: San Diego Co.


Location of Anza-Borrego Desert

Fossils from the Anza-Borrego Desert come from a large number of localities, with pertinent ages ranging from Blancan to Irvingtonian. Because of the large number of localities within the park along with the large size of the park, a single dot is made to stand for the entire area. Figure 1 indicates fossil areas.

Age. Late Blancan to Irvingtonian for this account. For purposes here, Late Blancan is considered to originate with the start of the Pleistocene at 2.6 mya, with the Blancan/Irvingtonian transition at 1.8 mya, keeping in mind however that the Blancan/Irvingtonian transition is just that, with overlaps between typical Late Blancan and Early Irvingtonian taxa. Some researchers, (e. g., Cassiliano 2006) consider the Irvingtonian to have commenced somewhat later, at about 1.4 mya. I have relied heavily on Cassiliano (1999) to place taxa as earlier than Pleistocene, and thus not considered here, or within the Pleistocene time span.

Anza-Borrego State Park boundaries

Fig. 1. Locality map, Anza-Borrego Desert State Park. BW = Big Wash; BB = Borrego Badlands; CB = Carrizo Badlands CL = Clark Lake; CCB = Coyote Canyon Badlands; FCB = Fish Creek Badlands; HC = Hawk Canyon; TR = Truckhaven Rocks; VB = Vallecito Creek Badlands. Adapted from Murray (2008).

General Description and Discussion. Fossils from the Anza-Borrego State Park come primarily from the deposits noted in Fig. 1, and most interpretation has involved the Vallecito Creek badlands. Downs and White (1968) noted that there are more than 12,000 ft of superposed deposits (including pre-Pleistocene). Downs and White (1968) named three faunas: the Layer Cake fauna (pre-Pleistocene Blancan), the Arroyo Seco fauna (probable Late Blancan [Early Pleistocene]), and Vallecito Creek fauna (Irvingtonian). They emphasized that these faunas lack defined boundaries and were used for purposes of clearer reference. Dates given by Cassiliano (1999) for the Arroyo Seco fauna (5.58-2.58 mya), however, suggests that virtually all of the Arroyo Seco fauna is pre-Pleistocene and is so considered here. The Vallecito Creek fauna, then, includes the Pleistocene portion of the Late Blancan and a considerable portion of the Irvingtonian.

Cassiliano (1999) gave faunal lists for the local faunas named by Downs and White (1968), but the accuracy of these lists is expected to display the limitations noted by Murray (2008: see below). The non-mammalian faunas are especially iffy in terms of chronology; it is quite possible that some taxa recorded here predate the Irvingtonian and that taxa recovered from Irvingtonian deposits have been omitted. Gensler et al. (2006) have added some data regarding the lower vertebrates beyond those given in Cassiliano (1999), and these have been included. The birds (Jefferson 2006) adds a number of taxa beyond those identified by Howard (1963), but for the most part without chronological data; a flamingo and the Sandhill Crane have been added to the list on the basis of a figure caption.

Murray (2008) upended many of the earlier suppositions regarding chronology and taxa, going critically through identification and locality data of the Anza-Borrego faunal collections. The mammals of the faunal list given here replace the mammals of earlier faunal lists. See Murray (2008) for detailed reasons for changes from earlier faunal lists. The same inadequacies that called for radical changes in the mammal list undoubtedly contribute to a degree of chaos among the other taxonomic lists, but mostly cannot be resolved at present. I have relied on Murray (2008) to decide on which of the named Pleistocene mammalian taxa should be included.

In the mammal list, a taxon followed by an asterisk was considered a Local Taxon Nudum by Murray (2008), who described the term as referring "to any taxon name that appears on any ABD [Anza-Borrego Desert] faunal list, but for which no catalogue number, specimen description, or diagnosis was ever published, and at least one catalogued specimen appears on the database or other archived documents identified to that taxon." Thus identifications of these taxa have a low level of confidence. Some of these would seem to be likely, while others unlikely. I have in these cases decided whether or not to include them on their taxon account on subjective grounds, hopefully aided by information contained in the literature. A number of other taxa are somewhat more secure, but still with relatively low levels of confidence. Genera not followed by a species nomen or "sp." implies there may be more than one species; "sp." implies a single species.

Because of what I perceive as insufficient published data on the geographic and chronologic limits, I have reluctantly decided to list all the faunal elements as the Anza-Borrego Desert Fauna ("Anza-Borrego" in the taxon accounts), though trying to limit the list to the Pleistocene Blancan and Irvingtonian. Thus all geographic localities (Fig. 1) are included. However, those taxa with citation to "Cassiliano 1999" are those from his list of the Vallecito fauna and include the majority of taxa. In the taxon accounts, I have listed many as just Late Blancan/Irvingtonian, but have listed under narrower chronological spans when judged possible.

Some taxa are presumed to be present but fall into the "Retired Taxa" category of Murray (2008). For the most part, these have been omitted. Likewise such taxa as Equus Species A and Equus Species B (where the Species A of one author may be different from that of a different author have been omitted. The overall exercise of trying to put together an accurate faunal list for the Anza-Borrego has been frustrating and the final list obviously less accurate than desirable. Equally sobering is the likelihood that major faunal lists of other localities have similar weaknesses as those seen here by Murray (2008), but without benefit of studies similar to his.

Anza-Borrego Desert Fauna.


Gila sp.—Chub (Gensler et al. 2006)
Ptychocheilus lucius—Pike Minnow (Gensler et al. 2006)
Xyrauchen texanus—Razorback Sucker (Gensler et al. 2006: cf.)


Anaxyrus sp.—True Toads (Cassiliano 1999)

Bufo sp.


Actinemys pallida—Southern Western Pond Turtle (Cassiliano 1999)

Clemmys marmorata

Trachemys scripta—Slider (Cassiliano 1999)

Pseudemys scripta

Kinosternon sonoriense—Sonoran Mud Turtle (Gensler et al. 2006: cf.)
Gopherus agassizii—Agassiz's Desert Tortoise (Cassiliano 1999)
Hesperotestudo sp.—Hesperotestudo Tortoises (Cassiliano 1999)

Geochelone sp.


Elgaria sp.—Alligator Lizards (Gensler et al. 2006)

Gerrhonotus sp.

Heloderma sp.—Gila Monsters (Gensler 2001)
Dipsosaurus sp.—Desert Iguanas (Cassiliano 1999)
Iguana iguana—Green Iguana (Cassiliano 1999)
Callisaurus sp.—Zebratail Lizards (Cassiliano 1999)
Phrynosoma anzaense—Anza Horned Lizard (Cassiliano 1999)
Sceloporus magister—Desert Spiny Lizard (Cassiliano 1999)
Uta stansburiana—Side-blotched Lizard (Cassiliano 1999)
Plestiodon sp.—Skinks (Cassiliano 1999)

Eumeces sp. (Cassiliano 1999)

Ameivra/Aspidoscelis—Jungle-runner or Whiptail (Cassiliano 1999)

Ameivra or Cnemidophorus

Xantusia downsi—Down's Night Lizard (Cassiliano 1999)
Lampropeltis getula—Common Kingsnake (Cassiliano 1999)
Masticophis flagellum—Coachwhip (Cassiliano 1999)
Crotalus sp.—Rattlesnakes (Cassiliano 1999)
Hypsiglena sp.—Nightsnakes (Cassiliano 1999)
Thamnophis sp.—Garter Snakes (Cassiliano 1999)


Anas acuta—Northern Pintail (Howard 1963: ?)
Anas clypeata—Northern Shoveler (Howard 1963)
Anser sp.—Extinct Goose (Howard 1963)
Brantadorna downsi—Down's Taradorn (Howard 1963)
Bucephala fossilis—Fossil Bufflehead (Howard 1963)
Melanitta perspicillata—Surf Scoter (Howard 1963: ?)
Oxyura bessomi—Bessom's Ruddy Duck (Howard 1963)
Callipepla gambelii—Gambel's Quail (Howard 1963)

Lophortyx gambeli

Agriocharis anza—Anza Turkey (Howard 1963)
Podiceps sp.—Extinct Grebe (Howard 1963)
Podiceps nigricollis—Eared Grebe (Howard 1963)

Podiceps caspicus

Phoenicopterus sp.—Extinct Flamingo (Jefferson 2006)
Teratornis incredibilis—Incredible Teratorn (Howard 1963)
Aquila chrysaetos—Golden Eagle (Howard 1963: ?)
Neophrontops vallecitoensis—Vallecito Neophrontops (Howard 1963)
Grus canadensis—Sandhill Crane (Jefferson 2006)
Fulica americana—American Coot (Olson 1974)

Howard (1963) described †Fulica hesterna from the Fish Creek/Vallecito Creek fauna; Olson (1974) reidentified the material as Fulica americana, thus rendering F. hesterna as a synonym of F. americana.

Charadrius vociferus—Killdeer (Howard 1963)
Asio sp.—Extinct Owl (Howard 1963)
Corvus sp.—Ravens and Relatives (Jefferson 2006)


Mammuthus columbi—Columbian Mammoth (Murray 2008)

McDaniel and Jefferson (2006), following Agenbroad (2001), considered M. columbi to be a synonym of M. imperator and thus listed occurrences from Anza-Borrego as M. columbi rather than M. imperator.

Mammuthus meridionalis—Southern Mammoth (Murray 2008)
Rhynchotherium*—Snouted Gomphotheres (Murray 2008)
Stegomastodon sp.—Stegodonts (Murray 2008)
Megalonyx jeffersoni*—Jefferson's Ground Sloth (Murray 2008)
Megalonyx wheatleyi—Wheatley's Ground Sloth (Murray 2008)
Nothrotheriops shastensis—Shasta Ground Sloth (Murray 2008)
Paramylodon harlani—Harlan's Ground Sloth (Murray 2008)
Castor—Beavers (Murray 2008)
Chaetodipus/Perognathus*—/Spiny or Silky Pocket Mice (Murray 2008)

Perognathus sp.

Dipodomys compactus—Gulf Coast Kangaroo Rat (Murray 2008)
Dipodomys hibbardi—Hibbard's Kangaroo Rat (Murray 2008)
Dipodomys sp. A—Unpublished, unnamed kangaroo rat (Murray 2008)
Dipodomys sp. B—Unpublished, unnamed kangaroo rat (Murray 2008)

The above two species were described with diagnoses in a M.S. thesis, but not formally named or published by Cunningham (1984) according to Murray (2008)

Chaetodipus/Perognathus sp. A—Unpublished, unnamed pocket mouse (Murray 2008)
Chaetodipus/Perognathus sp. B—Unpublished, unnamed pocket mouse (Murray 2008)

The above two species were described with diagnoses in a M.S. thesis by Gensler (2002), according to Murray (2008)

Microdipodops sp.—Kangaroo Mouse (Murray 2008: ?)
Geomys anzensis—Anza-Borrego Desert Pocket Gopher (Becker and White 1981)
Geomys garbanii—Garbani's Pocket Gopher (Becker and White 1981)
Thomomys—Western Pocket Gophers (Murray 2008)
"Lasiopodomys" morphotype—Lasiopodomys-like vole (Murray 2008)
Microtus with five triangles—Primitive vole (Murray 2008)
Microtus meadensis—Mead Vole (Murray 2008)
Mimomys (Cosomys) sp.—Water Voles (Murray 2008)

According to Murray (2008), probably referable to Ophiomys parvus.

Mictomys vetus—Ancient Bog Lemming (Murray 2008)
Ondatra idahoensis*—Idaho Muskrat (Murray 2008)
Ophiomys parvus—Ophiomys Vole (Murray 2008)
Baiomys—Pygmy Mice (Murray 2008)
Calomys (Bensonomys)*—Extinct Vesper Mice (Murray 2008)
Neotoma c—Unnamed Woodrat c (Murray 2008)
Neotoma e—Unnamed Woodrat e (Murray 2008)
Onychomys*—Grasshopper Mice (Murray 2008)
Peromyscus*—Deer Mice (Murray 2008)
Reithrodontomys*—Harvest Mice (Murray 2008)
Sigmodon minor—Dwarf Cotton Rat (Murray 2008)
Erethizon bathygnathum—Extinct Porcupine (Murray 2008)
Pewelagus dawsonae—Dawson's Rabbit (Murray 2008)
Sylvilagus floridanus—Eastern Cottontail (Murray 2008: cf.)
Sylvilagus hibbardi—Hibbard's Cottontail (Murray 2008)
Notiosorex*—Notiosorex Shrews (Murray 2008)
Sorex*—Long-tailed Shrews (Murray 2008)
Scapanus malatinus—Malatinus Mole (Murray 2008)
Felis rexroadensis—Rexroad Cat (Murray 2008)
Felis Smaller than Lynx rufus—Small Cat (Murray 2008)
Felis size of Lynx rufus*—Bobcat-size Cat (Murray 2008)
Miracinonyx inexpectatus—American Cheetah-like Cat (Murray 2008)
Panthera onca—Jaguar (Murray 2008)
Smilodon gracilis—Gracile Sabertooth (Murray 2008)
Borophagus diversidens—Bone-eating Dog (Murray 2008)
Canis size of modern C. lupus—Wolf size of modern Gray Wolf (Murray 2008)
Canis size modern C. latrans and C. lepophagus*—Canid size of Coyote and Johnson's Coyote (Murray 2008)
Canis edwardii/priscolatrans—Edward's Wolf or Wolf Coyote (Murray 2008)
Urocyon—Gray Foxes (Murray 2008)
Arctodus simus—Giant Short-faced Bear (Murray 2008)
Tremarctos floridanus—Florida Spectacled Bear (Murray 2008)
Satherium priscinarium—Extinct Otter (Murray 2008)
Taxidea taxus—American Badger (Murray 2008)
Trigonictis macrodon—Big-toothed Grison (Murray 2008)
Spilogale—Spotted Skunks (Murray 2008)
Bassariscus casei—Case's Ringtail (Murray 2008)
Nasua sp.—Coatimundi (Murray 2008)
Procyon rexroadensis—Rexroad Raccoon (Murray 2008: cf.)
Equus enormis—Enormous Horse (Murray 2008)
Equus francescana*—Francescan Horse (Murray 2008: cf.)
Equus pacificus—Pacific Horse (Murray 2008: ?)
Equus simplicidens—American Zebra (Murray 2008: cf.)
Hippidion sp.—Hippidion Horses (Murray 2008: cf. gen.)
Tapirus merriami—Merriam's Tapir (Murray 2008)
Platygonus—Flat-headed Peccaries (Murray 2008)
Blancocamelus meadei—Meade's Camel (Murray 2008)
Camelops—American Camels (Murray 2008)
Camelops hesternus*—Yesterday's Camel (Murray 2008)
Camelops minidokae*—Minidoka Camel (Murray 2008)
Gigantocamelus spatula—Giant Camel (Murray 2008)
Hemiauchenia blancoensis*—Blanco Llama (Murray 2008)
Hemiauchenia macrocephala*—Big-headed Llama (Murray 2008)
Hemiauchenia sp.—Undescribed Llama (Webb et al. 2006)
Paleolama—Ancient Llama (Webb et al. 2006)
Odocoileini size range of modern Odocoileus—Odocoileini Tribe (Murray 2008)
Cervus*—Elk (Murray 2008)
Antilocapra americana—Pronghorn (Murray 2006)
Capromeryx arizonensis—Arizona Diminutive Pronghorn (Murray 2006)
Stockoceros sp.—Stock's Pronghorn (Murray 2008: cf. gen.)
Euceratherium/Soergelia sp.—Shrub or Soergel's Oxen (Murray 2006)

Literature. Becker and White 1981; Cassiliano 1999, 2006; Cunningham 1984; Downs and White 1968; Gensler 2001, 2002; Gensler et al. 2006); Jefferson and Lindsay 2006); Howard 1963; McDaniel and Jefferson 2006; Murray 2006; Murray 2008; Olson 1974; Webb et al. 2006.


Last Update: 8 Apr 2014