Given the question: Information:  - 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.  - Eusthenodon is a genus of prehistoric lobe-finned fish. "Eusthenodon" lived during the Late Devonian period (Frasnian to Famennian faunal stages), around 385 to 359 million years ago. Remains of "Eusthenodon" have been found in Greenland, Russia, South Africa and more recently in Belgium for the first time. This genus belonged to the family Tristichopteridae, a clade which became extinct at the end of the Devonian. This family is known for some large genera, such as "Hyneria". "Eusthenodon" was about long, and among palaeontologists it is regarded as one of the most derived form of this group.  - Hyneria is a genus of prehistoric predatory lobe-finned fish that lived during the Devonian period around 360 million years ago.  - Vascular plants (from Latin "vasculum": duct), also known as tracheophytes (from the equivalent Greek term "trachea") and also higher plants, form a large group of plants (c. 308,312 accepted known species ) that are defined as those land plants that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They also have a specialized non-lignified tissue (the phloem) to conduct products of photosynthesis. Vascular plants include the clubmosses, horsetails, ferns, gymnosperms (including conifers) and angiosperms (flowering plants). Scientific names for the group include Tracheophyta and Tracheobionta.  - Belgium , officially the Kingdom of Belgium, is a sovereign state in Western Europe bordered by France, the Netherlands, Germany, Luxembourg, and the North Sea. It is a small, densely populated country which covers an area of and has a population of about 11 million people. Straddling the cultural boundary between Germanic and Latin Europe, Belgium is home to two main linguistic groups: the Dutch-speaking, mostly Flemish community, which constitutes about 59% of the population, and the French-speaking, mostly Walloon population, which comprises 41% of all Belgians. Additionally, there is a small group of German-speakers who live in the East Cantons located around the High Fens area, and bordering Germany.  - In evolutionary biology, adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches. Starting with a recent single ancestor, this process results in the speciation and phenotypic adaptation of an array of species exhibiting different morphological and physiological traits. An example of adaptive radiation would be the avian species of the Hawaiian honeycreepers. Via natural selection, these birds adapted rapidly and converged based on the different environments of the Hawaiian islands.  - An arthropod (from Greek "arthro-", joint + "podos", foot) is an invertebrate animal having an exoskeleton (external skeleton), a segmented body, and jointed appendages (paired appendages). Arthropods form the phylum Arthropoda, which includes the insects, arachnids, myriapods, and crustaceans.  Arthropods are characterized by their jointed limbs and cuticle made of chitin, often mineralised with calcium carbonate. The arthropod body plan consists of segments, each with a pair of appendages. The rigid cuticle inhibits growth, so arthropods replace it periodically by moulting. Their versatility has enabled them to become the most species-rich members of all ecological guilds in most environments. They have over a million described species, making up more than 80% of all described living animal species, some of which, unlike most animals, are very successful in dry environments.  - Tristichopterids ( Tristichopteridae ) were a diverse and successful group of tetrapodomorph fishes living throughout the Middle and Late Devonian . They first appeared in the Givetian stage of the Middle Devonian . Within the group sizes ranged from a few tens of centimeters ( Tristichopterus ) to several meters ( Hyneria and Eusthenodon ) . Some tristichopterids share some of the features of the elpistostegalians , a paraphyletic assemblage of fishes close to the origin of tetrapods . This mainly concerns the shape of the skull and a reduction in size of the posterior fins . An old and persistent notion is that Eusthenopteron was able to crawl onto land using its fins . However , there is no evidence actually supporting this idea . All tristichopterids went extinct by the end of Late Devonian .  - A fish is any member of a group of organisms that consist of all gill-bearing aquatic craniate animals that lack limbs with digits. They form a sister group to the tunicates, together forming the olfactores. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Tetrapods emerged within lobe-finned fishes, so cladistically they are fish as well. However, traditionally fish are rendered obsolete or paraphyletic by excluding the tetrapods (i.e., the amphibians, reptiles, birds and mammals which all descended from within the same ancestry). Because in this manner the term "fish" is defined negatively as a paraphyletic group, it is not considered a formal taxonomic grouping in systematic biology. The traditional term pisces (also ichthyes) is considered a typological, but not a phylogenetic classification.  - Tristichopterus is a genus of prehistoric lobe-finned fish which lived during the Devonian period. "Tristichopterus" belongs to the family Tristichopteridae.  - The Silurian is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago (Mya), to the beginning of the Devonian Period, Mya. As with other geologic periods, the rock beds that define the period's start and end are well identified, but the exact dates are uncertain by several million years. The base of the Silurian is set at a major Ordovician-Silurian extinction event when 60% of marine species were wiped out.  - England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west. The Irish Sea lies northwest of England and the Celtic Sea lies to the southwest. England is separated from continental Europe by the North Sea to the east and the English Channel to the south. The country covers five-eighths of the island of Great Britain (which lies in the North Atlantic) in its centre and south; and includes over 100 smaller islands such as the Isles of Scilly, and the Isle of Wight.  - The Devonian is a geologic period and system of the Paleozoic, spanning 60 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. Various terrestrial arthropods also became well-established. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the "Age of Fish". The first ray-finned and lobe-finned bony fish appeared, while the placodermi began dominating almost every known aquatic environment.  - Placodermi (from the Greek  = plate and  = skin, literally "plate-skinned") is an extinct class of armoured prehistoric fish, known from fossils, which lived from the Silurian to the end of the Devonian Period. Their head and thorax were covered by articulated armoured plates and the rest of the body was scaled or naked, depending on the species. Placoderms were among the first jawed fish; their jaws likely evolved from the first of their gill arches. Placoderms are paraphyletic, and consist of several distinct outgroups or sister taxa to all living jawed vertebrates, which originated among their ranks. This is illustrated by a 419-million-year-old fossil, "Entelognathus", from China, which is the only known placoderm with a type of bony jaw like that found in modern bony fishes. This includes a dentary bone, which is found in humans and other tetrapods. The jaws in other placoderms were simplified and consisted of a single bone. Placoderms were also the first fish to develop pelvic fins, the precursor to hindlimbs in tetrapods, as well as true teeth. 380-million-year-old fossils of three other genera, "Incistoscutum", "Materpiscis" and "Austroptyctodus", represent the oldest known examples of live birth.  - Plants are mainly multicellular, predominantly photosynthetic eukaryotes of the kingdom Plantae.  - FOREST (short for "Freedom Organisation for the Right to Enjoy Smoking Tobacco") is a United Kingdom political pressure group which campaigns against tobacco control activity.  - 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.    Given the information above, choose from the list below the object entity that exhibits the relation 'taxon rank' with the subject 'tristichopteridae'.  Choices: - class  - family  - form  - genus  - group  - kingdom  - phylum  - species  - variety
The answer is:
family