Editing Amplexus (section)

===Anurans===
Amplexus chiefly occurs aquatically, but some terrestrial [[Frog|anurans]] (frogs and toads) like the [[disc-tongued frog]]s ([[Discoglossidae]]) perform amplexus on land. In crown-group anurans, like the true frogs ([[Ranidae]]), the [[tree frog]]s (Hylidae), and the true toads ([[Bufonidae]]), amplexus is axillary (in the armpits). Other anurans (the [[Archaeobatrachia]], [[Sooglossidae]] and [[Myobatrachidae]]), show the ancestral state which is inguinal or lumbar amplexus (abdominal, in front of the hindlegs). Some species show cephalic amplexus where the head of the female is held while others show complete lack of amplexus.<ref name=Duellman&Trueb/> Additionally, anurans species have been observed to engage in multiple amplexus, which can also be referred to as a mating ball, as many toads attach themselves to a female trying to initiate amplexus.<ref name=":8">{{Cite journal|last1=Lod|first1=Thierry|last2=Lesbarr|first2=David|date=2004|title=Multiple paternity in Rana dalmatina, a monogamous territorial breeding anuran|journal=Naturwissenschaften|volume=91|issue=1|pages=44–47|doi=10.1007/s00114-003-0491-7|pmid=14740104|issn=0028-1042|bibcode=2004NW.....91...44L|s2cid=21612515}}</ref> However, multiple amplexus is not common among anurans, which could indicate that the costs associated with multiple amplexus are higher than the advantages associated with it.<ref name=":8" /> For female anurans, the idea of multiple amplexus would probably be more advantageous, because mating with more than one male would increase fertilization chances or increase offspring genetic diversity.<ref name=":8" /> Multiple amplexus would typically be common in explosive breeding amphibians, when there is a larger number of adults ready to breed at a breeding site in a short period of time.<ref name=":02" /> When this occurs female amphibians are viewed as a very important resource for males, as there are typically more males present than females, thus leading to more chances for multiple amplexus to occur.<ref name=":02" />

In most anurans, the males deposit sperm onto the eggs as they are being laid, however males of the genus ''[[Ascaphus]]'' possess an [[intromittent organ]], unique among anurans, for internal fertilization.  Internal fertilization does occur in a few other genera, including ''[[Nectophrynoides]]'', ''[[Mertensophryne]]'', and ''[[Eleutherodactylus]]''.<ref name=Duellman&Trueb>Duellman, W. E. and L. Trueb. 1986. Biology of Amphibians. New York: McGraw-Hill Publishing Company.</ref><ref>Linzey, D. 2001. Vertebrate Biology, McGraw Hill Publishers, New York.</ref>