In the section of the amphibia aortic arches, Kardong says:

"In amphibians, the first 2 aortic arches disappear early in development"
...
"the section of ventral aorta between arches III and IV becomes the common carotid artery"

However, XAO has:

[Term]
id: XAO:0000345
name: external carotid artery
namespace: xenopus_anatomy
def: "The artery which arises from aortic arch 1 at NF stage 45 and delivers blood to the filter apparatus. It is visible as a bilateral pair of vessels on the ventral surface of the head, running between the heart and the tip of the jaw." [PMID:12606281]
xref: AAO:0010416
is_a: XAO:0000114 ! artery
relationship: develops_from XAO:0000342 ! aortic arch 1
relationship: start_stage XAO:1000057 ! NF stage 45

Could this be an error resulting from confusion with the pharyngeal numbering system?

If it's correct, can you provide a reference?

Reported by: cmungall

Original Ticket: obo/xenopus-anatomy-xao-term-requests/8