1. CLASS AMPHIBIAOrder Anura • Ca. 4750 species worldwide (the most diverse group within Amphibia) • Cosmopolitan distribution (except where limited by extremely cold or xeric climates) • High reproductive diversity • Mostly external fertilization • Few internal fertilization (e.g., Ascaphus) • Direct development • Few viviparous species Agalychnis callidryas

2. Family Pelobatidae • 3 genera, 10 species (Holarctic distribution) • NA genera: Scaphiopus, Spea (1 genus in Europe: Pelobates) • Terrestrial, fossorial (sharp-edged spade on hind feet) • External fertilization Scaphiopus couchii

3. Scaphiopus vs. Spea • Scaphiopus: Spade on hindfoot elongated, sickle-shaped • Spea: Spade on hindfoot short, rounded, wedge-shaped

4. Pelobatids of Nevada • Great Basin Spadefoot (Spea intermontana)

5. Family Bufonidae • 33 genera, 376 species • Cosmopolitan distribution (except Greenland, Australia, Antarctica) • Mostly terrestrial • External fertilization (except few genera with internal fertilization, viviparity, or direct development) Bufo boreas Bufo alvarius

6. Family Bufonidae • Most species with paratoid glands (producing toxins; Neotropical genus, Atelopus, produces Tetrodotoxin, just like the Salamandrid genus Taricha) Bufo marinus Bufo terrestris

7. Bufo alvarius • Largest western toad • Enlarged warts on hindlegs All maps found in this presentation are from ARMI Atlas for Amphibian distribution

8. Bufo boreas • Usually rather indistinct white or cream-colored dorsal stripe • Lack of cranial crests

9. Bufo cognatus • Large toad with well defined pale-bordered dark blotches, in symmetrical pairs on its back • Cranial crests diverge widely towards rear of head

10. Bufo debilis • A small toad • Green or yellow green with small dark spots and bars on its back • Cranial crests weak or absent

11. Bufo exsul • Small dark-colored toad • Extremely small distribution • White or cream below with dark blotches

12. Bufo marinus • Introduced species from Central America • Large toad with deeply pitted paratoid glands extending far down sides of body

13. Bufo punctatus • Small toads with flattened head and body • Paratoid glands are round

14. Bufo speciosus • Medium-sized toad, uniformly warty, and with no dorsal stripe • Cranial crest weak or absent • Large inner metatarsal tubercle elongate and sharp-edged

15. Bufo valliceps • Broad, dark lateral stripe bordered above by a light stripe • Cranial crests strongly developed • Deep “valley” down center of the head

16. Bufo woodhousii • White dorsal stripe • Prominent cranial crest • Elongate paratoid glands

17. Bufo microscaphus • Back usually without prominent dark spotting • Skin relatively smooth

18. Bufonids of Nevada Bufo nelsoni Bufo boreas Bufo microscaphus Bufo cognatus Bufo alvarius? Bufo woodhousii Bufo punctatus