page_title: Nothomyrmecia
section_title: Genetics and phylogeny
hierarchical_section_title: Nothomyrmecia / Taxonomy / Genetics and phylogeny
caption_attribution_description: English: Prionomyrmex janzeni specimen
context_page_description: Nothomyrmecia, also known as the dinosaur ant or dawn ant, is a rare genus of ants consisting of a single species, Nothomyrmecia macrops. These ants live in South Australia, nesting in old-growth mallee woodland and Eucalyptus woodland. The full distribution of Nothomyrmecia has never been assessed, and it is unknown how widespread the species truly is; its potential range may be wider if it does favour old-growth mallee woodland. Possible threats to its survival include habitat destruction and climate change. Nothomyrmecia is most active when it is cold because workers encounter fewer competitors and predators such as Camponotus and Iridomyrmex, and it also increases hunting success. Thus, the increase of temperature may prevent them from foraging and very few areas would be suitable for the ant to live in. As a result, the IUCN lists the ant as Critically Endangered.
  As a medium-sized ant, Nothomyrmecia measures 9.7–11 mm. Workers are monomorphic, showing little morphological differentiation among one another. Mature colonies are very small, with only 50 to 100 individuals in each nest.
context_section_description: Studies show that all hymenopteran insects that have a diploid (2n) chromosome count above 52 are themselves all ants; Nothomyrmecia and another Ponerinae ant, Platythyrea tricuspidata, share the highest number of chromosomes within all the Hymenoptera, having a diploid chromosome number of 92–94.
  Genetic evidence suggests that the age of the most recent common ancestor for Nothomyrmecia and Myrmecia is approximately 74 million years old, giving a likely origin in the Cretaceous. There are two hypotheses of the internal phylogeny of Nothomyrmecia: subfamily Formicinae is more closely related to Nothomyrmecia than it is to Myrmecia, evolving from Nothomyrmecia-like ancestors. Alternatively, Nothomyrmecia and Aneuretinae may have shared a common ancestor; the two most likely separated from each other, and the first formicines evolved from the Aneuretinae instead. Currently, scientists agree that Nothomyrmecia most likely evolved from ancestors to the Ponerinae. Nothomyrmecia and other primitive ant genera such as Amblyopone and Myrmecia exhibit behaviour similar to a clade of soil-dwelling families of vespoid wasps. The following cladogram generated by Canadian entomologist S. B. Archibald and his colleagues shows the possible phylogenetic position of Nothomyrmecia among some ants of the subfamily Myrmeciinae. They suggest that Nothomyrmecia may be closely related to extinct Myrmeciinae ants such as Avitomyrmex, Macabeemyrma, Prionomyrmex, and Ypresiomyrma.
caption: Nothomyrmecia and the extinct Prionomyrmex are closely related to each other
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