The short-horned lizard is often referred to as a “horned toad” or “horny toad” because its squat, flattened shape and short, blunt snout give it a toad-ish look. There are over a dozen recognized species found in the deserts and semi-arid environments of North and Central America, from southern Canada to Guatemala.
Species are distinguishable by the formidable crown of horns adorning their head and the numerous spines across their back.In order to ward off hungry predators, short-horned lizards are capable of inflating their bodies up to twice their size, resembling a spiny balloon. And if this proves insufficient, some species employ one of the animal kingdom’s most bizarre defensive mechanisms: They shoot blood from their eyes.The ominous squirting blood emanates from ducts in the corners of their eyes and can travel a distance of up to three feet.
Over recent decades short-horn lizard populations have been in decline throughout their range. Destruction of their native habitat, efforts to eradicate ants—their staple food—and the pet trade have all contributed to this.
Krötenechsen (Phrynosoma) bilden eine Gattung kurzschwänziger und kurzbeiniger Echsen aus der Ordnung der Leguanartigen. Sie sind gekennzeichnet durch hornartige, verteidigungswirksame Fortsätze an Kopf und Rücken. Ihre deutsche Bezeichnung verdanken diese skurrilen Echsen ihrer krötenähnlichen Körperform. Ihr Körper ist 8 bis 13 Zentimeter lang. Krötenechsen leben in Wüstengebieten in Mexiko und im Südwesten der Vereinigten Staaten. Ihre Nahrung besteht überwiegend aus Ameisen.
Krötenechsen sind Einzelgänger und begegnen sich in der Natur fast ausschließlich zur Paarung. Die Tiere sind tagaktiv und verbringen die meiste Zeit mit der Suche nach oder dem Auflecken von Ameisen und anderen kleinen Beutetieren. In ihrem natürlichen Lebensraum vergraben sich die Tiere bei Regen oder kühlen Temperaturen im Sand. Scheint die Sonne, kommt zuerst der Kopf der Krötenechsen zum Vorschein, der restliche Körper bleibt mit Sand bedeckt, bis die Tiere ihre Vorzugstemperatur erreicht haben. Dieses Verhalten bietet ihnen die Möglichkeit, die Umgebung in Ruhe zu beobachten und dabei optimal getarnt zu sein. Haben sich die Tiere aufgewärmt, gehen sie auf Futtersuche. In der Mittagszeit, wenn es zu heiß wird, suchen die Wüstenkrötenechsen den Schatten von Felsen und Sträuchern oder vergraben sich wieder im Sand.
Krötenechsen weisen morphologische Ähnlichkeiten zum in Australien beheimateten Dornteufel auf. Andere Gemeinsamkeiten betreffen einige Verhaltensweisen in der Verteidigung und in der Ernährung. Krötenechsen bilden zusammen mit ihren australischen Verwandten ein Beispiel für eine konvergente Evolution.
Zur Verteidigung gegenüber Angreifern stehen der Krötenechse mehrere Mittel zur Verfügung; die Farbgebung ist Camouflage und entspricht etwa den Farben ihres Habitats. Bei einem Angriff ist die erste Reaktion die Schreckstarre. Ist der Angreifer bereits zu nah, legt sie kurze Sprints zurück, auf die abrupte Starre-Pausen folgen, um sich als visuelles Ziel dem Angreifer zu entziehen. Schlägt das fehl, bläst sich die Echse ähnlich einem Kugelfisch auf. Das Tier ist nun größer und als Nahrung möglicherweise uninteressant geworden.
Vier Arten verfügen über die Möglichkeit des Reflexblutens.[1][2][3] Hierbei bringt die Echse Gefäße am Augenrand zum Platzen. Blut sammelt sich in einer Höhle unter dem Augenlid und kann mit Hilfe von Muskeln 1,5 Meter weit verspritzt werden. Diese Art der Verteidigung funktioniert nur gegenüber Angreifern, die sich vom Geruch oder Geschmack des Blutes abschrecken lassen, z. B. Hunde. Sie wird nur im äußersten Notfall eingesetzt, da sich der Bluthaushalt um etwa ein Viertel reduziert.
Um sich gegen ein Aufheben über Kopf-/Nackenbereich zu wehren, duckt die Krötenechse ihren Kopf, so dass sich die am Kopf befindlichen Stacheln aufrichten. Um sich einem Aufgabeln über den Körper zu entziehen, presst sie diesen fest gegen den Untergrund oder gräbt ihn teilweise ein.
Krötenechsen (Phrynosoma) bilden eine Gattung kurzschwänziger und kurzbeiniger Echsen aus der Ordnung der Leguanartigen. Sie sind gekennzeichnet durch hornartige, verteidigungswirksame Fortsätze an Kopf und Rücken. Ihre deutsche Bezeichnung verdanken diese skurrilen Echsen ihrer krötenähnlichen Körperform. Ihr Körper ist 8 bis 13 Zentimeter lang. Krötenechsen leben in Wüstengebieten in Mexiko und im Südwesten der Vereinigten Staaten. Ihre Nahrung besteht überwiegend aus Ameisen.
Hestóhkáhne hova-éve.
Phrynosoma, whose members are known as the horned lizards, horny toads, or horntoads, is a genus of North American lizards and the type genus of the family Phrynosomatidae. Their common names refer directly to their horns or to their flattened, rounded bodies, and blunt snouts.
The generic name Phrynosoma means "toad-bodied". In common with true toads (amphibians of the family Bufonidae), horned lizards tend to move sluggishly, often remain motionless, and rely on their remarkable camouflage to avoid detection by predators. They are adapted to arid or semiarid areas. The spines on the lizard's back and sides are modified reptile scales, which prevent water loss through the skin, whereas the horns on the head are true horns (i.e., they have a bony core). Of the 21 species of horned lizards, 15 are native to the USA. The largest-bodied and most widely distributed of the American species is the Texas horned lizard.
Horned lizards use a variety of means to avoid predation. Their coloration generally serves as camouflage. When threatened, their first defense is to remain motionless to avoid detection. If approached too closely, they generally run in short bursts and stop abruptly to confuse the predator's visual acuity. If this fails, they puff up their bodies to cause them to appear more horned and larger so that they are more difficult to swallow.[1]
At least eight species (P. asio, P. cornutum, P. coronatum, P. ditmarsi, P. hernandesi, P. orbiculare, P. solare, and P. taurus) are also able to squirt an aimed stream of blood from the corners of the eyes for a distance up to 5 ft (1.5 m).[2][3][4][5] They do this by restricting the blood flow leaving the head, thereby increasing blood pressure and rupturing tiny vessels around the eyelids. The blood not only confuses predators, but also tastes foul to canine and feline predators. It appears to have no effect against predatory birds. Only three closely related species (P. mcallii, P. modestum, and P. platyrhinos) are certainly known to be unable to squirt blood.[3]
While previous thought held that compounds were added to the blood from glands in the ocular sinus cavity, current research has shown that the chemical compounds that make up the defense are already in the circulating blood.[3][4] It is possible that their diet of large quantities of venomous harvester ants could be a factor; however, the origin and structure of the chemicals responsible are still unknown. The blood-squirting mechanism increases survival after contact with canine predators;[4] the trait may provide an evolutionary advantage. Ocular autohemorrhaging has also been documented in other lizards,[6] which suggests blood-squirting could have evolved from a less extreme defense in the ancestral branch of the genus. Recent phylogenic research supports this claim, so the species incapable of squirting blood apparently have lost the adaptation for reasons yet unstudied.[7]
To avoid being picked up by the head or neck, a horned lizard ducks or elevates its head and orients its cranial horns straight up, or back. If a predator tries to take it by the body, the lizard drives that side of its body down into the ground so the predator cannot easily get its lower jaw underneath.
A University of Texas publication notes that horned lizard populations continue to disappear throughout their distribution despite protective legislation. Population declines are attributed to a number of factors, including the fragmentation and loss of habitat from real estate development and road construction, the planting of non-native grasses (both suburban and rural), conversion of native land to pastureland and agricultural uses, and pesticides. Additionally predation by domestic dogs and cats place continued pressure upon horned lizards.[8]
Fire ants (Solenopsis invicta), introduced from South America via the nursery industry's potted plants, pose a significant threat to all wildlife including horned lizards. Phrynosoma species do not eat fire ants. Fire ants kill many species of wildlife, and are fierce competitors against the native ants, which horned lizards require for food (with their specialized nutritional content). Fire ants have given all ants a bad reputation, and human attempts to eradicate ants, including invasive species and the native species on which the lizards prey, contribute to the continued displacement of native ant species and decline of horned lizards.[8]
The Texas horned lizard (Phrynosoma cornutum) has disappeared from almost half of its geographic range. Their popularity in the early to mid-20th-century pet trade, where collectors took thousands from the wild populations to sell to pet distributors, without provision for their highly specialized nutritional needs (primarily formic acid from harvester ants), resulted in certain death for almost all the collected lizards. In 1967, the state of Texas passed protective legislation preventing the collection, exportation, and sale of Phrynosoma, and by the early 1970s, most states enacted similar laws to protect and conserve horned lizards in the USA. As recently as the early 2000s, though, the state of Nevada still allowed commercial sale of Phrynosoma species. Despite limited federal protection in Mexico, horned lizards are still offered in Mexican "pet" markets throughout the country.[8]
In 2014, the Center for Biological Diversity in Tucson petitioned the Oklahoma Department of Wildlife Conservation to have the Texas horned lizard put on the endangered species list due to the massive declines of its population in Oklahoma, where it was once plentiful. The center said it may later seek protection for the animal on a federal level; it also said that reptiles in general are dying off at up to 10,000 times their historic extinction rate, greatly due to human influences.[9]
The following 21 species (listed alphabetically by scientific name) are recognized as being valid by the Reptile Database, three species of which have recognized subspecies:[10]
Note: In the above list, a binomial authority or trinomial authority in parentheses indicates that the species or subspecies was originally described in a genus other than Phrynosoma.
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Blainville's horned lizard (P. blainvillii)
Short-tailed horned lizard (P. braconnieri), Oaxaca, Mexico (20 May 2013).
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Texas horned lizard (P. cornutum), Armstrong County, Texas, USA (28 April 2013)
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Coast horned lizard (P. coronatum), San Luis Obispo County, California, USA (June 14, 2008)
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Coast horned lizard (P. coronatum) (25 April 2009)
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Greater short-horned lizard (P. douglassi brevirostre), Sweetwater County, Wyoming, USA (15 June 2016).
Pygmy short-horned lizard (P. douglasii), Washington, USA (5 June 2014)
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Mountain short-horned lizard (P. hernandesi), Culberson County, Texas, USA (19 May 2018)
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Flat-tailed horned lizard (P. mcallii) (9 November 2010)
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Round-tail horned lizard (P. modestum), Municipality of Tula, Tamaulipas, Mexico (15 August 2004)
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Mountain horned lizard (P. orbiculare orientale), Municipality of Miquihuana, Tamaulipas, Mexico (24 September 2009)
Desert horned lizard (P. platyrhinos), San Bernardino County, California, USA (9 July 2019)
Regal horned lizard (P. solare), Apache Junction, Arizona, USA (25 March 2007)
The genus of horned lizards is the official state reptile of Wyoming.[11] Texas designated the Texas horned lizard (Phrynosoma cornutum) as the official state reptile in 1993[12] and the "TCU Horned Frog" is the mascot of Texas Christian University in Fort Worth, Texas. TCU is the only known athletic team with the horned lizard as a mascot.
The TCU mascot is commonly known as Super frog to TCU fans and students. He is usually present at TCU sporting events.
Horned lizard on a necktie at El Paso, Texas, in 1940
Phrynosoma, whose members are known as the horned lizards, horny toads, or horntoads, is a genus of North American lizards and the type genus of the family Phrynosomatidae. Their common names refer directly to their horns or to their flattened, rounded bodies, and blunt snouts.
The generic name Phrynosoma means "toad-bodied". In common with true toads (amphibians of the family Bufonidae), horned lizards tend to move sluggishly, often remain motionless, and rely on their remarkable camouflage to avoid detection by predators. They are adapted to arid or semiarid areas. The spines on the lizard's back and sides are modified reptile scales, which prevent water loss through the skin, whereas the horns on the head are true horns (i.e., they have a bony core). Of the 21 species of horned lizards, 15 are native to the USA. The largest-bodied and most widely distributed of the American species is the Texas horned lizard.
Los lagartos cornudos, llora sangres o erróneamente llamados camaleones (Phrynosoma) son un género de lagartos de la familia Phrynosomatidae. Se caracterizan por tener el cuerpo aplanado en forma oval con una hilera de espinas rodeando los costados y una especie de cuernos en la cabeza. La forma y número de los cuernos en la cabeza varía según la especie. Sus especies se distribuyen por América, desde el sur de Canadá hasta Guatemala.
Se reconocen las siguientes 21 especies:[1][2]
Los lagartos cornudos, llora sangres o erróneamente llamados camaleones (Phrynosoma) son un género de lagartos de la familia Phrynosomatidae. Se caracterizan por tener el cuerpo aplanado en forma oval con una hilera de espinas rodeando los costados y una especie de cuernos en la cabeza. La forma y número de los cuernos en la cabeza varía según la especie. Sus especies se distribuyen por América, desde el sur de Canadá hasta Guatemala.
Phrynosoma Phrynosomatidae familian sailkatzen den narrasti generoa da. Ipar Amerikan bizi dira.
Phrynosoma Phrynosomatidae familian sailkatzen den narrasti generoa da. Ipar Amerikan bizi dira.
Phrynosoma, parfois appelé lézards à cornes ou iguanes à cornes, est un genre de sauriens de la famille des Phrynosomatidae[1].
Les 22 espèces de ce genre se rencontrent en Amérique du Nord[1].
Selon Reptarium Reptile Database (14 mai 2016)[2] :
Phrynosoma, parfois appelé lézards à cornes ou iguanes à cornes, est un genre de sauriens de la famille des Phrynosomatidae.
Paddeiguaner er en slekt av iguaner. De fleste lever i det vestlige USA og Mexico, men to arter går inn i Canada, og en art går inn i Guatemala.
De har en rund kropp, og et kort hode, noe som gjør at de kan ligne på en padde. På hodet og ryggen har de hornaktige utvekster. Dette minner om den australske torndjevelen, selv om de ikke er nært beslektet. Et annet likhetstrekk med torndjevelen er at paddeiguanene hovedsakelig eter maur, så de to gruppene er et godt eksempel på konvergent evolusjon.
Når paddeiguanene blir angrepet, kan de sprute blod på fienden fra øyekroken. Noen arter legger egg, mens andre føder levende unger. De lever i forskjellige habitater fra ørken og prærie til barskog og høyfjell i Rocky Mountains.
Paddeiguaner er en slekt av iguaner. De fleste lever i det vestlige USA og Mexico, men to arter går inn i Canada, og en art går inn i Guatemala.
De har en rund kropp, og et kort hode, noe som gjør at de kan ligne på en padde. På hodet og ryggen har de hornaktige utvekster. Dette minner om den australske torndjevelen, selv om de ikke er nært beslektet. Et annet likhetstrekk med torndjevelen er at paddeiguanene hovedsakelig eter maur, så de to gruppene er et godt eksempel på konvergent evolusjon.
Når paddeiguanene blir angrepet, kan de sprute blod på fienden fra øyekroken. Noen arter legger egg, mens andre føder levende unger. De lever i forskjellige habitater fra ørken og prærie til barskog og høyfjell i Rocky Mountains.
Multimedia w Wikimedia Commons Phrynosoma − rodzaj jaszczurki z rodziny frynosomowatych (Phrynosomatidae).
Rodzaj obejmuje gatunki występujące w Ameryce Północnej[3].
Ciało frynosom jest szerokie i spłaszczone. Ogon krótki, szeroki u nasady. Tył głowy, a u niektórych gatunków również boki ciała są pokryte rzędem ostro zakończonych kolców[4].
Phrynosoma: gr. φρυνη phrunē, φρυνης phrunēs „ropucha”[5]; σωμα sōma, σωματος sōmatos „ciało”[6].
Do rodzaju należą następujące gatunki[3]:
Phrynosoma − rodzaj jaszczurki z rodziny frynosomowatych (Phrynosomatidae).
Phrynosoma[1] este un gen de șopârle din familia Phrynosomatidae.[1]
Cladograma conform Catalogue of Life[1]:
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Acest articol referitor la o reptilă este un ciot. Puteți ajuta Wikipedia prin completarea sa. 角蜥（學名：Phrynosoma）是角蜥科下的一屬蜥蜴。牠們的身體圓形，吻頓。背上及兩側有棘，這些棘都是變化了的鱗片，而頭上有角。在北美洲共有14個物種，單在美國就有8種。在美國體型最大及分佈最廣的是德州角蜥。
角蜥的形態像澳洲的魔蜥，但卻只是遠親。牠們之間也有一些獨特的相似地方，如坐著等待獵物及獵食蟻等，故牠們是趨同演化的好例子。
角蜥會使用多種方式來避免被掠食。牠們的顏色一般都是一種偽裝。當受到威脅時，牠們會留在原地不動，以避免被發現。若威脅接近時，牠們會立即彈走，並突然停下，令掠食者的視覺出現誤差。若仍未能避開掠食者，牠們會膨脹身體，使其外觀好像有很多角般，感覺難以下咽。
最少有4個物種能夠在眼角射出達5呎遠的血液。[1][2][3]牠們會限制血液離開頭部，用以增加血壓及爆破近眼睛的細小血管。這樣不單可以嚇怕掠食者，而其血液的氣味就犬科及貓科來說是很難嗅的。不過，這種方式卻對掠食性的鳥類沒有作用。牠們很多時會將頭仰向上，讓其角直立，避免從空中來的掠食者抓著頭部。
紅收獲蟻佔了大部份角蜥的食性60-90%。牠們也會吃白蟻、甲蟲、蟋蟀、草蜢及其他細小的昆蟲。
在加利福尼亞州、德克薩斯州及其他州份，角蜥已經瀕危，並得到保護。德州角蜥已經減少了約30%，但卻有回升的跡象。牠們衰落的原因主要是棲息地的破壞、其他南美洲入侵的蟻影響了紅收獲蟻的數量、與及過度使用殺蟲劑等。[4]
角蜥（學名：Phrynosoma）是角蜥科下的一屬蜥蜴。牠們的身體圓形，吻頓。背上及兩側有棘，這些棘都是變化了的鱗片，而頭上有角。在北美洲共有14個物種，單在美國就有8種。在美國體型最大及分佈最廣的是德州角蜥。
サバクツノトカゲ（砂漠角蜥蜴、学名：Phrynosoma platyrhinos）は、イグアナ科（ツノトカゲ科とする説もあり）ツノトカゲ属に分類されるトカゲ。
アメリカ合衆国（アイダホ州、カリフォルニア州北東部、ネバダ州北部、モンタナ州南部、ユタ州北部）
アメリカ合衆国（アリゾナ州西部、カリフォルニア州南東部、ネバダ州南部、ユタ州南部）、メキシコ（ソノラ州、バハカリフォルニア州北部）
全長7-13cm。体形は非常に扁平。体側面には襞状の鱗が1列に並ぶ。腹面の鱗は滑らか。後頭部にはやや短い角状の鱗がある。背面には赤、褐色、白、灰色などの複雑な斑紋が入る。
基底が砂や砂礫の、砂漠や荒地などに生息する。昼行性。危険を感じると体を平たくして相手をやり過ごすか、茂みの中へ逃げこむ。また口を大きく開けて相手に噛みつき威嚇することもある。さらに眼から相手の眼を目掛けて、天敵であるイヌやオオカミが嫌う成分が含まれている血液を射出することもある。この時、体内の三分の一の血液を放出する。血液を最大1m先まで飛ばすことができる[1]。
食性は動物食の強い雑食で、主にアリを食べるが、植物質を食べることもある。
繁殖形態は卵生。6-7月に1回に2-16個の卵を産む。卵は50-60日で孵化する。
ペット用として流通されることがあり、日本にも輸入されている。野生個体だけでなく飼育下繁殖個体が流通することもある。飼育は難しく、日本国内では飼育下繁殖だけではなく長期飼育例も少ない。テラリウムで飼育される。シート状の遠赤外線ヒーターや保温用の電球などで保温し、それとは別に昼間（もしくは照明と合わせて一定持間）小型の保温用の電球などをケージの中へ照射し局所的に高温になる場所を作る。照明として紫外線照射量の多い専用の蛍光灯やメタルハライドランプを一定時間点灯する。水容器を設置しても容器から水を飲むことはまずなく脱水症状を起こすこともあるため、ケージの壁面に霧吹きをしたりスポイトを用いて直接的に水を与える。餌は必ずしもアリのみを与える必要はないと考えられているが、大量の小型昆虫（コオロギの幼虫など）を比較的高い頻度で与える必要がある。
この項目は、動物に関連した書きかけの項目です。この項目を加筆・訂正などしてくださる協力者を求めています（Portal:生き物と自然／プロジェクト:生物）。
뿔도마뱀(Horned lizard)은 북아메리카에서 사는 뿔도마뱀속이고 뿔도마뱀과의 일종이다. 흔한 이름은 납작하고 둥근 몸, 그리고 무딘 코를 통해 생겨난 은유이다.
유전자 이름은 "신체 하중"을 의미한다. 큰 개구리과와 두꺼비과 마찬가지로 뿔도마뱀들은 느리게 움직이는 경향이 있어서 그들을 잡기 쉽게 만든다. 이것은 또한 포식자들의 공격을 피할 수도 있다. 그들은 건조지역이나 반건조지역에 적응한다. 도마뱀의 등과 옆구리의 가시는 피부를 통한 수분 손실을 막는 변형된 파충류 비늘로 만들어진 반면, 머리의 뿔은 진짜 뿔이다. 뿔도마뱀 22종 중에서 15종은 미국 토종이다. 가장 크고 널리 분포된 미국 종은 텍사스뿔도마뱀이다.
