Fossil Dogs and Wolves of Anza-Borrego Desert State Park
Ancient Canids of Southern California

Members of the dog family, Canidae, have been among the most adaptable and successful predators in North America for millions of years. The fossil record preserved in Anza-Borrego Desert State Park documents a diverse assemblage of fossil dogs, wolves, foxes, and related canids that inhabited the region during the Pliocene and Pleistocene.
These animals occupied a variety of ecological roles, ranging from small omnivorous fox-like species to large pack-hunting predators. Their fossils help scientists understand the evolution of carnivores and the changing environments of southern California through time.

Dogs in Ancient Anza-Borrego
The landscapes of ancient Anza-Borrego were home to a rich variety of mammals, including horses, camels, mammoths, ground sloths, antelope, bears, and cats. Canids were an important part of these ecosystems and evolved alongside many of these species.
Some canids were specialized predators capable of pursuing prey across open grasslands and floodplains. Others were opportunistic omnivores that fed on a variety of foods. Together they occupied ecological roles similar to those of modern wolves, coyotes, foxes, and other members of the dog family.

The fossil record demonstrates that canids were among the most widespread and successful carnivores in North America.

Wolves, Foxes, and Their Relatives
The fossil deposits of Anza-Borrego preserve evidence of several canid lineages. Some species were closely related to modern wolves and coyotes, while others represent extinct branches of the dog family.

Among the most famous North American canids is the dire wolf, Canis dirus, a large predator that lived during the late Pleistocene. Dire wolves were larger and more heavily built than modern gray wolves and likely hunted many of the large herbivores that inhabited Ice Age California.

Smaller fox-like species also occupied the region, demonstrating the ecological diversity of the canid family.

Evolutionary Success
Canids became one of the most successful groups of mammalian predators because of their adaptability. Unlike many specialized carnivores, members of the dog family were able to exploit a wide range of habitats and food sources.

Their evolutionary history provides important evidence for:
  • Predator-prey relationships
  • Adaptation to environmental change
  • Carnivore evolution
  • Mammalian dispersal and migration
  • Development of modern ecosystems
Because canids evolved rapidly and occupied many ecological niches, their fossils are particularly valuable to paleontologists studying changing environments through time.

What Canid Fossils Tell Us
Fossil dogs and wolves help scientists reconstruct:
  • Ancient food webs
  • Carnivore communities
  • Climate and habitat changes
  • Mammalian evolution
  • Predator competition with cats, bears, and other carnivores
Together with fossils of saber-toothed cats and bears, canids help reveal the complex predator communities that once existed in southern California.

Explore a Fossil in 3D
Rotate, zoom, and examine this specimen from the Anza-Borrego Desert State Park collections.
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Interactive 3D Model: Dentary - Canidae Borophagus
Specimen Information
  • Catalog Number: LACM4924 V123906
  • Element: Dentary
  • Formation: Hueso
  • Epoch: Pleistocene
  • Age: Irvingtonian
  • Group: Palm Spring
  • Locality: Fish Creek / Vallecito Creek
  • Scanned using Agisoft Metashape
  • Specimen © California State Parks. 3D model produced by the Anza-Borrego Desert State Park Paleontology Society.
Why Anza-Borrego Matters
Anza-Borrego Desert State Park preserves one of the most important late Cenozoic mammal records in North America. Fossil canids are an important component of this record and provide valuable evidence of carnivore evolution during the Pliocene and Pleistocene.

The diversity of fossil dogs recovered from the park reflects the dynamic environments that once occupied the region and helps scientists understand how predator communities changed through time.

Fossil Record
  • Bone-eating dog (Borophagus diversidens)
  • Armbruster's wolf (Canis armbrusteri)
  • Wolf coyote (Canis priscolatrans)
  • Johnston's wolf (Canis lepophagus)
  • Coyote (Canis latrans)
  • Gray fox (Urocyon)
  • Fox (Vulpes)


Quick Facts
  • Family: Canidae
  • Includes: Wolves, foxes, coyotes, and extinct fossil dogs
  • Famous species: Canis dirus (dire wolf)
  • Age: Pliocene and Pleistocene
  • Role: Predators and omnivores
  • Significance: Evidence of changing carnivore communities
  • Location: Anza-Borrego Desert State Park, California

​Learn More
Read Chapter 12, "The Small Carnivorans: Canids, Felids, Procyonids, Mustelids ," in Fossil Treasures of the Anza-Borrego Desert for a detailed discussion of fossil dogs, wolves, and the evolution of canids in Anza-Borrego Desert State Park.