Common names: Autlán rattlesnake.

Crotalus lannomi is a venomous

Venomous snake

"Poisonous snake" redirects here. For true poisonous snakes, see Rhabdophis.Venomous snakes are snakes which have venom glands and specialized teeth for the injection of venom...

 pitviper

Crotalinae

The Crotalinae, commonly known as "pit vipers" or crotaline snakes, are a subfamily of venomous vipers found in Asia and the Americas. They are distinguished by the presence of a heat-sensing pit organ located between the eye and the nostril on either side of the head...

 species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 found in Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 in Jalisco

Jalisco

Jalisco officially Estado Libre y Soberano de Jalisco is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is located in Western Mexico and divided in 125 municipalities and its capital city is Guadalajara.It is one of the more important states...

. Known from only a single specimen. No subspecies are currently recognized.

Description

Known only from a single specimen: a female 63.8 cm in length that is presumed to be an adult. The presence of some larger scales on top of its head and a longer tail are traits that Tanner (1966) suggested are primitive. Mostly on this basis, he opinion was that this species is most closely related to C. stejnegeri

Crotalus stejnegeri

Crotalus stejnegeri is a venomous pitviper species found in western Mexico. No subspecies are currently recognized.-Description:Adults do not usually grow to more than 60 cm in length. The greatest length recorded for a specimen is 72.4 cm. The tail is relatively long, representing 11-14.8% of the...

, even though its head and body are not as slender as that of C. stejnegeri.

Geographic range

Found in western Mexico

Mexico

The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...

 in Jalisco

Jalisco

Jalisco officially Estado Libre y Soberano de Jalisco is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is located in Western Mexico and divided in 125 municipalities and its capital city is Guadalajara.It is one of the more important states...

. Known only from the type locality, which is given as "1.8 miles west of the pass, Puerto Los Mazos, or 22 miles west by road from the Río Tuxcacuesco, a branch of the Rio America on Mexican Highway No. 80, Jalisco, Mexico."

Conservation status

This species is classified as Data Deficient (DD) on the IUCN

World Conservation Union

The International Union for Conservation of Nature and Natural Resources is an international organization dedicated to finding "pragmatic solutions to our most pressing environment and development challenges." The organization publishes the IUCN Red List, compiling information from a network of...

 Red List of Threatened Species

IUCN Red List

The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...

(v3.1, 2001). Species are listed as such when there is inadequate information to make a direct, or indirect, assessment of its risk of extinction based on its distribution and/or population status. It may be well studied, and its biology well known, but appropriate data on abundance and/or distribution are lacking. Data Deficient is therefore not a category of threat. Listing of taxa in this category indicates that more information is required and acknowledges the possibility that future research will show that threatened classification is appropriate. It is important to make positive use of whatever data are available. In many cases great care should be exercised in choosing between DD and a threatened status. If the range of a taxon is suspected to be relatively circumscribed, and a considerable period of time has elapsed since the last record of the taxon, threatened status may well be justified. The population trend is unknown. Year assessed: 2007.