The terrestrial animal with greater heat tolerance lives in a desert larger than the United States

The largest warm desert in the Tiera surpasses a country like the United States in size and is approximately twice that of the Amazon rainforest: it measures 5,150 km from east to west, 1,280-2,250 from north to south.

It is the Sahara desert, which has an area of ​​9.1 million square kilometers. Here, in addition, lives the land animal best adapted to heat.
The desert ant Cataglyphis can survive at body temperatures of 53 ºC, while, in laboratory tests, the red honey ant (Melophorus bagoti) briefly reached 56.7 ºC.
more info about Cataglyphis in https://www.ncbi.nlm.nih.gov/pubmed/19250516?dopt=Abstract
https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/cataglyphis