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Pit viper
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<h2 id="evolution">Evolution</h2> <p>The earliest known fossil pit viper remains are from the <a href="/facts/Early_Miocene/Sm5gVSKd">Early Miocene</a> of <a href="/facts/Nebraska/g9hHfRFU">Nebraska</a>. As pit vipers are thought to have had an Asian origin before eventually colonizing the Americas, this suggests that they must have originated and diversified even earlier. During the Late Miocene, they reached as far west as eastern Europe, where they are no longer found; it is thought that they did not expand further into Europe.<a class="footnote-ref" id="fnref:12" href="#fn:12"><sup>12</sup></a> </p> <h2 id="geographic-range">Geographic range</h2> <p>The subfamily Crotalinae is found from <a href="/facts/Central_Asia/rB8k0CyT">Central Asia</a> eastward and southward to <a href="/facts/Japan/U5mz0SRT">Japan</a>, <a href="/facts/China/lTjIXY5p">China</a>, <a href="/facts/Indonesia/vQnWU3IW">Indonesia</a>, peninsular <a href="/facts/India/1kKHcnxM">India</a>, <a href="/facts/Nepal/yWCzTBR2">Nepal</a>, Bangladesh and <a href="/facts/Sri_Lanka/VtTBmysE">Sri Lanka</a>. In the Americas, they range from southern <a href="/facts/Canada/cWWFM8oc">Canada</a> southward to Central America to southern South America.<a class="footnote-ref" id="fnref:13" href="#fn:13"><sup>13</sup></a> </p> <h2 id="habitat">Habitat</h2> <p>Crotalines are a versatile subfamily, with members found in <a href="/facts/Habitat_(ecology)/zo1DN2gA">habitats</a> ranging from parched <a href="/facts/Desert/Mknp4bXq">desert</a> (e.g., the sidewinder, <i><a href="/facts/Crotalus_cerastes/MyIBxw9F">Crotalus cerastes</a></i>) to <a href="/facts/Rainforest/IEY5TMEc">rainforests</a> (e.g., the bushmaster, <i>Lachesis muta</i>). They may be either <a href="/facts/Arboreal/6C5AeQ2y">arboreal</a> or <a href="/facts/Terrestrial_animal/AhP2mont">terrestrial</a>, and at least one species (the cottonmouth, <i><a href="/facts/Agkistrodon_piscivorus/tEqQbD0W">Agkistrodon piscivorus</a></i>) is semiaquatic. The altitude record is held jointly by <i><a href="/facts/Crotalus_triseriatus/dKw0e6xI">Crotalus triseriatus</a></i> in Mexico and <i><a href="/facts/Gloydius_strauchi/eaWXApAu">Gloydius strauchi</a></i> in China, both of which have been found above the treeline at over 4,000 m above sea level.<a class="footnote-ref" id="fnref:14" href="#fn:14"><sup>14</sup></a> </p> <h2 id="behavior">Behavior</h2> <p>Although a few species of crotalines are highly active by day, such as <i><a href="/facts/Trimeresurus_trigonocephalus/QjYWhSB1">Trimeresurus trigonocephalus</a></i>, a bright green pit viper <a href="/facts/Endemic_(ecology)/xt4IpIsl">endemic</a> to Sri Lanka, most are nocturnal, preferring to avoid high daytime temperatures and to hunt when their favored prey are also active. The snakes' heat-sensitive pits are also thought to aid in locating cooler areas in which to rest.<a class="footnote-ref" id="fnref:15" href="#fn:15"><sup>15</sup></a> </p><p>As ambush predators, crotalines typically wait patiently somewhere for unsuspecting prey to wander by. At least one species, the arboreal <i><a href="/facts/Gloydius_shedaoensis/Gwhshteo">Gloydius shedaoensis</a></i> of China, is known to select a specific ambush site and return to it every year in time for the spring migration of birds. Studies have indicated these snakes learn to improve their strike accuracy over time.<a class="footnote-ref" id="fnref:16" href="#fn:16"><sup>16</sup></a> </p><p>Many temperate species of pit vipers (e.g. most rattlesnakes) congregate in sheltered areas or "dens" to overwinter (brumate, see <a href="/facts/Hibernation/oltroTtp">hibernation</a>), the snakes benefiting from the combined heat. In cool temperatures and while pregnant, pit vipers also bask on sunny ledges. Some species do not mass together in this way, for example the copperhead, <i><a href="/facts/Agkistrodon_contortrix/xWV72vKL">Agkistrodon contortrix</a></i>, or the Mojave rattlesnake, <i><a href="/facts/Crotalus_scutulatus/YIKDwVnA">Crotalus scutulatus</a></i>. </p><p>Like most snakes, crotalines keep to themselves and strike only if cornered or threatened. Smaller snakes are less likely to stand their ground than larger specimens. Pollution and the destruction of rainforests have caused many pit viper populations to decline. Humans also threaten pit vipers, as many are hunted for their skins or killed by cars when they wander onto roads. </p> <h2 id="reproduction">Reproduction</h2> <p>With few exceptions, crotalines are <a href="/facts/Ovoviviparity/sPk5JLTN">ovoviviparous</a>, meaning that the embryos develop within eggs that remain inside the mother's body until the offspring are ready to hatch, when the hatchlings emerge as functionally free-living young. In such species, the eggshells are reduced to soft membranes that the young shed, either within the reproductive tract, or immediately after emerging. </p><p>Among the <a href="/facts/Oviparous/oSgSIVHY">oviparous</a> (egg-laying) pit vipers are <i><a href="/facts/Lachesis_(genus)/gLprer1f">Lachesis</a></i>, <i><a href="/facts/Calloselasma/KSNo0BeP">Calloselasma</a></i>, and some <i><a href="/facts/Trimeresurus/8K6bmRzq">Trimeresurus</a></i> species. All egg-laying crotalines are believed to guard their eggs. </p><p>Brood sizes range from two for very small species, to as many as 86 for the fer-de-lance, <i><a href="/facts/Bothrops_atrox/qkz5TqzA">Bothrops atrox</a></i>, which is among the most prolific of all live-bearing snakes. </p><p>Many young crotalines have brightly coloured tails that contrast dramatically with the rest of their bodies. These tails are known to be used by a number of species in a behavior known as caudal luring; the young snakes make worm-like movements with their tails to lure unsuspecting prey within striking distance. <a class="footnote-ref" id="fnref:17" href="#fn:17"><sup>17</sup></a> </p> <h2 id="taxonomy">Taxonomy</h2> <p>In the past, the pit vipers were usually classed as a separate <a href="/facts/Family_(biology)/qTrn6E8E">family</a>: the Crotalidae. Today, however, the <a href="/facts/Monophyly/pD8Yrrn6">monophyly</a> of the <a href="/facts/Viperinae/vt5mKKEm">viperines</a> and the crotalines as a whole is undisputed, which is why they are treated here as a subfamily of the <a href="/facts/Viperidae/rS5298vz">Viperidae</a>. </p> <h2 id="genera">Genera</h2> <table><tbody><tr><th>Genus<a class="footnote-ref" id="fnref:18" href="#fn:18"><sup>18</sup></a></th><th>Taxon author<a class="footnote-ref" id="fnref:19" href="#fn:19"><sup>19</sup></a></th><th>Species<a class="footnote-ref" id="fnref:20" href="#fn:20"><sup>20</sup></a></th><th>Common name</th><th>Geographic range<a class="footnote-ref" id="fnref:21" href="#fn:21"><sup>21</sup></a></th></tr><tr><td><i><a href="/facts/Agkistrodon/HfX9mx7S">Agkistrodon</a></i></td><td><a href="/facts/Palisot_de_Beauvois/5G1pHeMN">Palisot de Beauvois</a>, 1799</td><td>6</td><td>Moccasins</td><td>North America from the northeastern and central USA southward through peninsular <a href="/facts/Florida/cF245A3Q">Florida</a> and southwestern <a href="/facts/Texas/B987WHF0">Texas</a>. In Central America on the Atlantic versant from <a href="/facts/Tamaulipas/T3r0THFN">Tamaulipas</a> and <a href="/facts/Nuevo_Le%C3%B3n/Hx950xAz">Nuevo León</a> southward to the <a href="/facts/Yucat%C3%A1n_Peninsula/xGAcABhC">Yucatán Peninsula</a>, <a href="/facts/Belize/2xVuhCTt">Belize</a> and <a href="/facts/Guatemala/MoMcSnla">Guatemala</a>. Along the Pacific coastal plain and lower foothills from <a href="/facts/Sonora/cmLLIFR9">Sonora</a> south through Guatemala, <a href="/facts/El_Salvador/6Plzw4vr">El Salvador</a>, <a href="/facts/Honduras/75jMlRQ1">Honduras</a> and <a href="/facts/Nicaragua/PsyPGXxm">Nicaragua</a> to northwestern <a href="/facts/Costa_Rica/baw0GTI1">Costa Rica</a>.</td></tr><tr><td><i><a href="/facts/Atropoides/f2r6jFGh">Atropoides</a></i></td><td>Werman, 1992</td><td>1</td><td>Picado's jumping pit viper</td><td>Costa Rica and western Panama</td></tr><tr><td><i><a href="/facts/Bothriechis/kdBSJDQ3">Bothriechis</a></i></td><td><a href="/facts/Wilhelm_Peters/7aYXe0ob">Peters</a>, 1859</td><td>11</td><td>Palm-pit vipers</td><td>Southern Mexico (southeastern <a href="/facts/Oaxaca/bt9HNw2z">Oaxaca</a> and the northern highlands of <a href="/facts/Chiapas/VS9UF8pw">Chiapas</a>), through Central America to northern South America (<a href="/facts/Colombia/nl7r8Q2u">Colombia</a>, western <a href="/facts/Venezuela/eX1qnkln">Venezuela</a>, <a href="/facts/Ecuador/Tdv7czY4">Ecuador</a> and northern <a href="/facts/Peru/dBt7XrYD">Peru</a></td></tr><tr><td><i><a href="/facts/Bothrocophias/ePnQ4ww5">Bothrocophias</a></i></td><td>Gutberlet & <a href="/facts/Jonathan_A._Campbell/bg8ezsvh">Campbell</a>, 2001</td><td>9</td><td>Toadheaded pit vipers</td><td>Northern South America</td></tr><tr><td><i><a href="/facts/Bothrops/9mALQp0w">Bothrops</a></i></td><td><a href="/facts/Johann_Georg_Wagler/7K0MXbq8">Wagler</a>, 1824</td><td>48</td><td>Lanceheads</td><td>Northeastern Mexico (Tamaulipas) southward through Central and South America to <a href="/facts/Argentina/aFSA5bAk">Argentina</a>; <a href="/facts/Saint_Lucia/fEUDuRwb">Saint Lucia</a> and <a href="/facts/Martinique/HTwzANWx">Martinique</a> in the <a href="/facts/Lesser_Antilles/e3kYAgTY">Lesser Antilles</a>; <a href="/facts/Ilha_da_Queimada_Grande/5K0rb1zJ">Ilha da Queimada Grande</a> off the coast of Brazil</td></tr><tr><td><i><a href="/facts/Calloselasma/KSNo0BeP">Calloselasma</a></i></td><td><a href="/facts/Edward_Drinker_Cope/Wup4Ic7k">Cope</a>, 1860</td><td>1</td><td>Malayan pit viper</td><td>Southeast Asia from <a href="/facts/Thailand/GCUnN4JK">Thailand</a> to northern <a href="/facts/Malaysia/8zbUMzCP">Malaysia</a> and <a href="/facts/Java/2MNA2rLm">Java</a>, <a href="/facts/Indonesia/vQnWU3IW">Indonesia</a></td></tr><tr><td><i><a href="/facts/Cerrophidion/h2f81UBz">Cerrophidion</a></i></td><td>Campbell & Lamar, 1992</td><td>5</td><td>Montane pit vipers</td><td>Southern Mexico (highlands of <a href="/facts/Guerrero/xwDwQMFI">Guerrero</a> and southeastern Oaxaca), southward through the highlands of Central America (Guatemala, El Salvador, Honduras, northern Nicaragua, Costa Rica) to western Panama</td></tr><tr><td><i><a href="/facts/Craspedocephalus/8K6bmRzq">Craspedocephalus</a></i></td><td><a href="/facts/Heinrich_Kuhl/Xz5gbv7a"> Kuhl</a> & <a href="/facts/Johan_Conrad_van_Hasselt/dnKLR1dh">van Hasselt</a>, 1822</td><td>15</td><td>Pit viper</td><td>India to <a href="/facts/Thailand/GCUnN4JK">Thailand</a> to northern <a href="/facts/Malaysia/8zbUMzCP">Malaysia</a> and <a href="/facts/Indonesia/vQnWU3IW">Indonesia</a></td></tr><tr><td><i><a href="/facts/Crotalus/EjKvmJeH">Crotalus</a></i>T</td><td><a href="/facts/Carl_Linnaeus/gy5HWkHS">Linnaeus</a>, <a href="/facts/10th_edition_of_Systema_Naturae/8H6KJrLJ">1758</a></td><td>51</td><td>Rattlesnakes</td><td>The Americas, from southern Canada to northern Argentina</td></tr><tr><td><i><a href="/facts/Deinagkistrodon/Cu9IPdKj">Deinagkistrodon</a></i></td><td><a href="/facts/Howard_K._Gloyd/d2ejVCYx">Gloyd</a>, 1979</td><td>1</td><td>Hundred-pace pit viper</td><td>Southeast Asia</td></tr><tr><td><i><a href="/facts/Garthius/rPXGmnTr">Garthius</a></i></td><td>Malhotra & Thorpe, 2004</td><td>1</td><td>Mount Kinabalu pit viper, Chasen's mountain pit viper</td><td><a href="/facts/Borneo/1aIGfyvV">Borneo</a></td></tr><tr><td><i><a href="/facts/Gloydius/KxkMdHrV">Gloydius</a></i></td><td>Hoge & Romano-Hoge, 1981</td><td>22</td><td>Asian moccasins</td><td>Russia, east of the <a href="/facts/Ural_Mountains/gzNoPkt6">Ural Mountains</a> through <a href="/facts/Siberia/oaCoPEjF">Siberia</a>, <a href="/facts/Iran/24yukge8">Iran</a>, the <a href="/facts/Himalayas/eRSf0yyE">Himalayas</a> from Pakistan, India, <a href="/facts/Nepal/yWCzTBR2">Nepal</a> and China, Korea, Japan and the <a href="/facts/Ryukyu_Islands/94rjkv8f">Ryukyu Islands</a></td></tr><tr><td><i><a href="/facts/Hypnale/Ir6zXEyc">Hypnale</a></i></td><td><a href="/facts/Leopold_Fitzinger/cuQkxDR9">Fitzinger</a>, 1843</td><td>3</td><td>Hump-nosed pit vipers</td><td><a href="/facts/Sri_Lanka/VtTBmysE">Sri Lanka</a> and India</td></tr><tr><td><i><a href="/facts/Lachesis_(genus)/gLprer1f">Lachesis</a></i></td><td><a href="/facts/Fran%C3%A7ois_Marie_Daudin/vkhDeknM">Daudin</a>, 1803</td><td>4</td><td>Bushmasters</td><td>Central and South America</td></tr><tr><td><i><a href="/facts/Metlapilcoatlus/bw8Bg6j0">Metlapilcoatlus</a></i></td><td>Campbell, Frost, & Castoe, 2019</td><td>6</td><td>Jumping pit vipers</td><td>The mountains of eastern Mexico southeastward on the Atlantic versant and lowlands though Central America to central <a href="/facts/Panama/GckVVhnp">Panama</a>. On the Pacific versant, they occur in isolated populations in east-central and southern Mexico, Guatemala, El Salvador, Costa Rica, and Panama.</td></tr><tr><td><i><a href="/facts/Mixcoatlus/xNwL3DlM">Mixcoatlus</a></i></td><td>Jadin, H.M.Smith & Campbell, 2011</td><td>3</td><td>Mexican pit vipers</td><td>Mexico</td></tr><tr><td><i><a href="/facts/Ophryacus/uwKby7S0">Ophryacus</a></i></td><td><a href="/facts/Edward_Drinker_Cope/Wup4Ic7k">Cope</a>, 1887</td><td>3</td><td>Mexican horned pit vipers</td><td>Mexico</td></tr><tr><td><i><a href="/facts/Ovophis/LUQvdYYa">Ovophis</a></i></td><td>Burger, 1981</td><td>7</td><td>Mountain pit vipers</td><td>Nepal and <a href="/facts/Seven_Sister_States/JtFJkH2A">Seven Sisters</a> (<a href="/facts/Assam/64Hs7TwB">Assam</a>) of India eastward through <a href="/facts/Myanmar/zcqQH2oE">Myanmar</a>, <a href="/facts/Cambodia/t1wJd6GU">Cambodia</a>, Thailand, <a href="/facts/Laos/S0afugjX">Laos</a>, <a href="/facts/Vietnam/0ulfA8Eq">Vietnam</a>, <a href="/facts/West_Malaysia/88WtYx31">West Malaysia</a>, <a href="/facts/Taiwan/VcJoUD8w">Taiwan</a>, Japan (<a href="/facts/Okinawa_Prefecture/2PNlxv5K">Okinawa</a>) and Indonesia (<a href="/facts/Sumatra/Fo192kJb">Sumatra</a>)</td></tr><tr><td><i><a href="/facts/Porthidium/ayfRukVL">Porthidium</a></i></td><td><a href="/facts/Edward_Drinker_Cope/Wup4Ic7k">Cope</a>, 1871</td><td>9</td><td>Hognose pit vipers</td><td>Mexico (<a href="/facts/Colima/tmnpDHmV">Colima</a>, Oaxaca and Chiapas on the Pacific side, the Yucatán Peninsula on the Atlantic side) southward through Central America to northern South America (Ecuador in the Pacific lowlands, northern Venezuela in the Atlantic lowlands)</td></tr><tr><td><i><a href="/facts/Protobothrops/yylPB21A">Protobothrops</a></i></td><td>Hoge & Romano-Hoge, 1983</td><td>14</td><td>Pit vipers</td><td>Asia</td></tr><tr><td><i><a href="/facts/Sistrurus/1JoNPovF">Sistrurus</a></i></td><td><a href="/facts/Samuel_Garman/1J6TQhhx">Garman</a>, 1883</td><td>3</td><td>Ground rattlesnakes</td><td>Southeastern Canada, eastern, central and northwestern USA, isolated populations in northern and central Mexico</td></tr><tr><td><i><a href="/facts/Trimeresurus/8K6bmRzq">Trimeresurus</a></i></td><td><a href="/facts/Bernard_Germain_de_Lac%C3%A9p%C3%A8de/3G5EEL32">Lacépède</a>, 1804</td><td>43</td><td>Asian lanceheads</td><td>Southeast Asia from India to southern China and Japan, and the <a href="/facts/Malay_Archipelago/RkeF5zR1">Malay Archipelago</a> to <a href="/facts/Timor/H4dozDNo">Timor</a></td></tr><tr><td><i><a href="/facts/Tropidolaemus/STzdYgdm">Tropidolaemus</a></i></td><td><a href="/facts/Johann_Georg_Wagler/7K0MXbq8">Wagler</a>, 1830</td><td>5</td><td>Temple vipers</td><td>Southern India and Southeast Asia</td></tr></tbody></table> <p><i>*) Not including the nominate subspecies.</i> T) <a href="/facts/Type_genus/vKbAuKph">Type genus</a>.<a class="footnote-ref" id="fnref:22" href="#fn:22"><sup>22</sup></a> </p> <h2 id="see-also">See also</h2> <ul><li><a href="/facts/List_of_crotaline_species_and_subspecies/JjmG6r0X">List of crotaline species and subspecies</a></li></ul> <h2 id="further-reading">Further reading</h2> <ul><li>Gumprecht, Andreas; Tillack, Frank (2004). "A proposal for a replacement name of the snake genus <i>Ermia</i> Zhang, 1993". <i>Russian Journal of Herpetology</i> 11: 73–76.</li> <li><a href="/facts/Albert_Hazen_Wright/3TQHVhno">Wright, Albert Hazen</a>; Wright, Anna Allen (1957). <i>Handbook of Snakes of the United States and Canada</i>. Ithaca and London: Comstock Publishing Associates, a Division of Cornell University Press. 1,105 pp. (in two volumes). (Seventh Printing 1985). ("Crotalidae", p. 901).</li> <li>Goris RC (2011). "Infrared organs of snakes: an integral part of vision". <i>Journal of Herpetology</i> 45: 2–14.</li></ul> <h2 id="external-links">External links</h2> Wikimedia Commons has media related to Crotalinae. <a href="/facts/Wikispecies/b2GhA7Le">Wikispecies</a> has information related to <i>Crotalinae</i>. <ul><li><a href="http://snakesarelong.blogspot.com/2012/09/snakes-that-can-see-without-eyes.html">Pit organs at Life is Short, but Snakes are Long</a></li></ul> <h2 id="references">References</h2> <ol> <li id="fn:1"><p>Mehrtens JM (1987). Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. ISBN 0-8069-6460-X. <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li> <li id="fn:2"><p>Sometimes spelled "pitvipers" – Campbell & Lamar, 2004 [page needed] <a href="/wiki/Wikipedia:Citing_sources" target="_blank">/wiki/Wikipedia:Citing_sources</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li> <li id="fn:3"><p>"Crotalinae". Integrated Taxonomic Information System. Retrieved 26 October 2006. <a href="https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=634394" target="_blank">https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=634394</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li> <li id="fn:4"><p>Campbell JA, Lamar WW (2004). The Venomous Reptiles of the Western Hemisphere. Ithaca and London: Comstock Publishing Associates. 870 pp., 1,500 plates. ISBN 0-8014-4141-2. <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li> <li id="fn:5"><p>Mehrtens JM (1987). Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. ISBN 0-8069-6460-X. <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li> <li id="fn:6"><p>Campbell JA, Lamar WW (2004). The Venomous Reptiles of the Western Hemisphere. Ithaca and London: Comstock Publishing Associates. 870 pp., 1,500 plates. ISBN 0-8014-4141-2. <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li> <li id="fn:7"><p>Mehrtens JM (1987). Living Snakes of the World in Color. New York: Sterling Publishers. 480 pp. ISBN 0-8069-6460-X. <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li> <li id="fn:8"><p>Parker HW, Grandison AGC. 1977. Snakes -- a natural history. Second Edition. British Museum (Natural History) and Cornell University Press. 108 pp. 16 plates. LCCCN 76-54625. ISBN 0-8014-1095-9 (cloth), ISBN 0-8014-9164-9 (paper). <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li> <li id="fn:9"><p>Bullock, T. H. and Diecke, F. P. J. (1956). Properties of an infrared receptor. Journal of Physiology 134, 47-87. <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li> <li id="fn:10"><p>Stidworthy J. 1974. Snakes of the World. Grosset & Dunlap Inc. 160 pp. ISBN 0-448-11856-4. <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li> <li id="fn:11"><p>Campbell JA, Lamar WW (2004). The Venomous Reptiles of the Western Hemisphere. Ithaca and London: Comstock Publishing Associates. 870 pp., 1,500 plates. ISBN 0-8014-4141-2. <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:11" class="footnote-back-ref">↩</a></p></li> <li id="fn:12"><p>"The first European pit viper from the Miocene of Ukraine - Acta Palaeontologica Polonica". www.app.pan.pl. Retrieved 21 February 2024. <a href="https://www.app.pan.pl/article/item/app44-327.html" target="_blank">https://www.app.pan.pl/article/item/app44-327.html</a> <a href="#fnref:12" class="footnote-back-ref">↩</a></p></li> <li id="fn:13"><p>McDiarmid RW, Campbell JA, Touré T (1999). Snake Species of the World: A Taxonomic and Geographic Reference, Volume 1. Washington, District of Columbia: Herpetologists' League. 511 pp. ISBN 1-893777-00-6 (series). ISBN 1-893777-01-4 (volume). <a href="https://fr.wikipedia.org/wiki/Roy_Wallace_McDiarmid" target="_blank">https://fr.wikipedia.org/wiki/Roy_Wallace_McDiarmid</a> <a href="#fnref:13" class="footnote-back-ref">↩</a></p></li> <li id="fn:14"><p>Campbell JA, Lamar WW (2004). The Venomous Reptiles of the Western Hemisphere. Ithaca and London: Comstock Publishing Associates. 870 pp., 1,500 plates. ISBN 0-8014-4141-2. <a href="/wiki/ISBN_(identifier)" target="_blank">/wiki/ISBN_(identifier)</a> <a href="#fnref:14" class="footnote-back-ref">↩</a></p></li> <li id="fn:15"><p>Krochmal, Aaron R.; Bakken, George S. (1 August 2003). "Thermoregulation is the pits: use of thermal radiation for retreat site selection by rattlesnakes". Journal of Experimental Biology. 206 (15): 2539–2545. doi:10.1242/jeb.00471. PMID 12819261. 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