Crotalus simus - Middle American rattlesnake

Meaning
culminates – “to crown, peak, summit” to reach its highest or lowest altitude
simus – take form Latin meaning “flat nosed”. Referring to the “blunt head” of this type of snake compared to other lanceheaded vipers (Bothrops).
tzabcan – is taken from the Mayan language meaning rattlesnake

Distribution
Found in Mexico down too Belize, Guatemala, El Salvador, Honduras and Nicaragua to west-central Costa Rica. It appears to be absent from Panama, but apparently does exist on the Atlantic side of Colombia.
C.s.culminates is found on the Southwestern side of Mexico in the constituent states Morelos, Guerrero, southwestern Oaxaca and probably western Puebla.
C.s.simus covers Southeastern part of Mexico (Veracruz, southeastern Oaxaca, Tabasco and Chiapas), plus the counties Guatemala, Honduras, Belize, El Salvador, Nicaragua, and Costa Rica.
C.s.tzabcan is found in the Mexican states (Yucatán, Campeche, Quintana Roo and eastern Tabasco) and in northern parts of Guatemala and Belize.

Habitat
Seen their large range they can be found in a variety of different habitats but are usually found in regions that are semiarid, including tropical, pine-oak forests that are dry, savanna, thorn woodland and arid scrub forest. It also occurs in mesic forests with dry open areas. Elevations usually below 1000m but in the highlands of Mexico between 1500 and 2200meters.

Description
This stout rattlesnake as an adult commonly exceed 130 cm in length. Males tend to grow larger than females reaching 140 too 160cm in some populations with a maximum reported length of 180 cm.
Like C. durissus a spinal ridge is present and like C.durissus the dorsal scales on the ridge are noticeable for their high tubercular keels.
The ground color varies with species and population, ranging form gray-brown, brown to red brown from yellowish-gray, blue-gray greenish-gray, straw-yellow or orange colored. The 21-32 rhombic or diamond shaped botches, not always visible, are with dark colors at the exterior and lighter/paler color inside and most have a paravertebral stripe starting from the top of their head running down part of the back. The tail of adults may be “patternless” or faint crossbands may be present.

Diet
Prey mainly consist out of mammals, including ground squirrels, mice, rats, rabbits and other other ground dwelling animals

Venom
The overall effect in humans causes: nausea, with pain, massive swelling, blistering and necrosis that often lead to physicians performing fasciotomies and in some cases amputations. Systemic effects are rare as are renal failure and neurotoxicity.

Extra
Only the venom from neonates contains crotoxin a toxin also found in

The taxa culminates and tzabcan where formerly listed under the Crotalus durissus group but by the use of molecular genetic data placed under C. simus.

Interesting in the distribution of C. simus is that they appear not to live in Panama even though it is bordered between Costa Rica and Colombia