Given the question: Information:  - Archosaurs are a group of diapsid amniotes whose living representatives consist of birds and crocodilians. This group also includes all extinct non-avian dinosaurs, extinct crocodilian relatives, and pterosaurs. Archosauria, the archosaur clade, is a crown group that includes the most recent common ancestor of living birds and crocodilians. It includes two main clades: Pseudosuchia, which includes crocodilians and their extinct relatives, and Ornithosuchia, which includes birds and their extinct relatives (such as non-avian dinosaurs and pterosaurs).  - Desmatosuchinae is one of the two subfamilies of aetosaurs, the other being Aetosaurinae. It is a stem-based taxon defined as all aetosaurs more closely related to "Desmatosuchus" than the last common ancestor of "Desmatosuchus" and "Stagonolepis". All synapomorphies that diagnose the clade can be found in the osteoderms. These include tongue-and-groove articulations for lateral plates present in dorsal presacral paramedian plates and large spikes on the lateral cervical, dorsal, and caudal plates.  - Aetosaurinae is one of the two subfamilies of aetosaurs , the other being Desmatosuchinae . It is a stem - based taxon defined as all aetosaurs more closely related to Aetosaurus than to the last common ancestor of Aetosaurus and Desmatosuchus . The only synapomorphy that diagnoses the clade Aetosaurinae is the medial offset of the dorsal eminences of the paramedian osteoderms . A phylogenetic study in 2012 found Aetosaurinae to be paraphyletic , with Aetosaurus being the basal-most stagonolepidid and aetosaurines like Calyptosuchus , Neoaetosauroides , and the newly described Aetobarbakinoides being successively more derived taxa leading up to a clade containing Desmatosuchinae and Typothoracisinae . Under this phylogeny , most traditional aetosaurines are more closely related to Desmatosuchus than they are to Aetosaurus , and the clade Aetosaurinae can only include Aetosaurus .  - South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded on the south by of coastline of Southern Africa stretching along the South Atlantic and Indian Oceans, on the north by the neighbouring countries of Namibia, Botswana and Zimbabwe, and on the east and northeast by Mozambique and Swaziland, and surrounding the kingdom of Lesotho. South Africa is the 25th-largest country in the world by land area, and with close to 56 million people, is the world's 24th-most populous nation. It is the southernmost country on the mainland of the Old World or the Eastern Hemisphere. It is the only country that borders both the Atlantic Ocean and the Indian Ocean. About 80 percent of South Africans are of Sub-Saharan African ancestry, divided among a variety of ethnic groups speaking different Bantu languages, nine of which have official status. The remaining population consists of Africa's largest communities of European (white), Asian (Indian), and multiracial (coloured) ancestry.  - Desmatosuchus (from Greek  "desmos" 'link' +  "soûkhos" 'crocodile') is an extinct genus of archosaur belonging to the Order Aetosauria. It lived during the Late Triassic.  - Neoaetosauroides is an extinct genus of primitive aetosaur. Its type and only species is "N. engaeus". Fossils have been found from the Los Colorados Formation outcropping along the Sierra Morada River in La Rioja, Argentina, and date back to the Norian age of the Late Triassic. It was the first aetosaur known from the formation, with remains being discovered in the 1960s.  - In biology, phylogenetics (Greek: ,  - "phylé", "phylon" = tribe, clan, race +  - "genetikós" = origin, source, birth) is the study of the evolutionary history and relationships among individuals or groups of organisms (e.g. species, or populations). These relationships are discovered through phylogenetic inference methods that evaluate observed heritable traits, such as DNA sequences or morphology under a model of evolution of these traits. The result of these analyses is a phylogeny (also known as a phylogenetic tree)  a diagrammatic hypothesis about the history of the evolutionary relationships of a group of organisms. The tips of a phylogenetic tree can be living organisms or fossils, and represent the "end," or the present, in an evolutionary lineage. Phylogenetic analyses have become central to understanding biodiversity, evolution, ecology, and genomes.  - Aetosaurus is an extinct genus of archosaur reptile belonging to the order Aetosauria. It is generally considered to be the most primitive aetosaur. Three species are currently recognized: "A. ferratus", the type species from Germany and Italy; "A. crassicauda" from Germany; and "A. arcuatus" from eastern North America. Additional specimens referred to "Aetosaurus" have been found from South Africa, the Chinle Group of the southwestern United States, and the Fleming Fjord Formation of Greenland. Specimens of "Aetosaurus" occur in Norian-age strata.  - Plants are mainly multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae.  - The Late Triassic is the third and final of three epochs of the Triassic Period in the geologic timescale. The Triassic-Jurassic extinction event began during this epoch and is one of the five major mass extinction events of the Earth. The corresponding series is known as the Upper Triassic. In Europe the epoch was called the Keuper, after a German lithostratigraphic group (a sequence of rock strata) that has a roughly corresponding age. The Late Triassic spans the time between Ma and Ma (million years ago). The Late Triassic is divided into the Carnian, Norian and Rhaetian ages.  - Typothoracisinae is a clade of aetosaurs within the subfamily Aetosaurinae. It is a stem-based taxon defined as all aetosaurs closer to "Typothorax" than to "Stagonolepis" or "Desmatosuchus". As with many aetosaur taxa, most of the synapomorphies that diagnose the clade are found in the osteoderms. These include a strongly acute angle of flexion between the dorsal and lateral flanges of the dorsal and lateral plates and triangular-shaped pelvic and anterior caudal dorsal lateral plates possessing semicircular borders and hook-like eminences.  - The Triassic is a geologic period and system which spans 50.9 million years from the end of the Permian Period million years ago (Mya), to the beginning of the Jurassic Period Mya. The Triassic is the first period of the Mesozoic Era. Both the start and end of the period are marked by major extinction events. The Triassic was named in 1834 by Friedrich von Alberti, after the three distinct rock layers ("tri" meaning "three") that are found throughout Germany and northwestern Europered beds, capped by marine limestone, followed by a series of terrestrial mud- and sandstonescalled the "Trias".  - Emil Hans Willi Hennig (April 20, 1913  November 5, 1976) was a German biologist who is considered the founder of phylogenetic systematics, also known as cladistics. In 1945 as a prisoner of war, Hennig began work on his theory of cladistics, which he published in 1950. With his works on evolution and systematics he revolutionised the view of the natural order of beings. As a taxonomist, he specialised in dipterans (ordinary flies and mosquitoes).  - Reptiles are tetrapod (four-limbed vertebrate) animals in the class Reptilia, comprising today's turtles, crocodilians, snakes, amphisbaenians, lizards, tuatara, and their extinct relatives. The study of these traditional reptile orders, historically combined with that of modern amphibians, is called herpetology.  - In biology and genealogy, the most recent common ancestor (MRCA, also "last common ancestor" LCA, or "concestor") of any set of organisms is the most recent individual from which all organisms in a group, for are directly descended. The term is also used reference to the ancestry of groups of genes (haplotypes) rather than organisms.  - In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoological names with "-inae".  - In phylogenetics, apomorphy and synapomorphy refer to derived characteristic of a clade. Apomorphy implies a characteristic that is different from the form of an ancestor, i.e., an innovation, of use in determining membership in a clade. Synapomorphy is a shared derived character or trait state that distinguishes a clade from other organisms. In other words, it is an apomorphy shared by members of a monophyletic group, and thus assumed to be present in their most recent common ancestor. The word synapomorphy, coined by German entomologist Willi Hennig, is derived from the Greek words ', "syn" = shared; ', "apo" = away from; and "", "morphe" = shape.A   - In zoological nomenclature, a type species ("species typica") is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen(s). A similar concept is used for suprageneric groups called a type genus.  - Calyptosuchus (meaning "covered crocodile") is an extinct genus of crurotarsan from the Late Triassic of North America. As an aetosaur, it was heavily armored and had a pig-like snout used to uproot plants. The genus might be a junior synonym of "Stagonolepis".  - A pig is any of the animals in the genus Sus, within the Suidae family of even-toed ungulates. Pigs include the domestic pig and its ancestor, the common Eurasian wild boar ("Sus scrofa"), along with other species; related creatures outside the genus include the peccary, the babirusa, and the warthog. Pigs, like all suids, are native to the Eurasian and African continents. Juvenile pigs are known as piglets. Pigs are highly social and intelligent animals.  - Typothorax is an extinct genus of typothoracisine aetosaur that lived in the Late Triassic. Its remains have been found in North America. Two species are known: "T. coccinarum", the type species, and "T. antiquum".  - Stagonolepis is an extinct genus of stagonolepidid aetosaur known from the Late Triassic (Carnian stage) of Europe.  - In biology, a species (abbreviated sp., with the plural form species abbreviated spp.) is the basic unit of biological classification and a taxonomic rank. A species is often defined as the largest group of organisms in which two individuals can produce fertile offspring, typically by sexual reproduction. While this definition is often adequate, looked at more closely it is often problematic. For example, in a species complex, the boundaries between closely related species become unclear or disappear altogether. Other ways of defining species include similarity of DNA, morphology, or ecological niche. The presence of locally adaptive traits may further subdivide species into infraspecific taxa such as subspecies.  - A genus ( genera) is a taxonomic rank used in the biological classification of living and fossil organisms in biology. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus.  - A clade (from , "klados", "branch") is a group of organisms that consists of a common ancestor and all its lineal descendants, and represents a single "branch" on the "tree of life".  - Aetosaurs ("aetosaur" ; order name "Aetosauria" ; from Greek, (aetos, "eagle") and (sauros, "lizard")) are an extinct order of heavily armoured, medium- to large-sized Late Triassic herbivorous archosaurs. They have small heads, upturned snouts, erect limbs, and a body covered by plate-like scutes. All aetosaurs belong to the family Stagonolepididae. Two distinct subdivisions of aetosaurs are currently recognized, Desmatosuchinae and Aetosaurinae, based primarily on differences in the morphology of the bony scutes of the two groups. Over 20 genera of aetosaurs have been described, and recently there has been controversy regarding the description of some of these genera.    After reading the paragraphs above, we are interested in knowing the entity with which 'aetosaurinae' exhibits the relationship of 'taxon rank'. Find the answer from the choices below.  Choices: - branch  - class  - family  - form  - genus  - group  - kingdom  - order  - series  - species  - subfamily  - subgenus  - tribe  - variety
The answer is:
subfamily