Pristis
Introduction '''''Pristis''''' is a genus of sawfish of the family Pristidae. These large fish are found worldwide in tropical and subtropical regions in coastal marine waters, estuaries, and freshwater lakes and rivers. Sawfish have declined drastically and all species are considered critically endangered today.
Taxonomy The scientific genus name ''Pristis'' is derived from the Greek word for saw.===Living species===Recent authorities recognize four species:* ''Pristis clavata'' Garman, 1906 — dwarf sawfish, Queensland sawfish* ''Pristis pectinata'' Latham, 1794 — smalltooth sawfish* ''Pristis pristis''  (Linnaeus, 1758)  — largetooth sawfish, common sawfish, freshwater sawfish, Leichhardt's sawfish* ''Pristis zijsron'' Bleeker, 1851 — longcomb sawfish, green sawfishThese are divided into two species groups. Most are considered a part of the smalltooth group, except ''P. pristis'' which is the sole member of the largetooth group. Two additional species, ''P. microdon'' and ''P. perotteti'', have historically been recognized, but in 2013 it was shown that they are conspecific with ''P. pristis'' as morphological and genetic differences are lacking, leading recent authorities to treat them as synonyms. ''Anoxypristis cuspidata'' was formerly included in ''Pristis'', but it has a number of distinctive features (for example, no teeth on the basal quarter of the saw) and recent authorities place it in its own genus.===Extinct species===According to Fossilworks, extinct ''Pristis'' species only known from fossil remains include:* ''Pristis acutidens'' Agassiz 1843* ''Pristis amblodon'' Cope 1869* ''Pristis aquitanicus'' Delfortrie 1871* ''Pristis atlanticus'' Zbyszewski 1947* ''Pristis bisulcatus'' Agassiz 1843* ''Pristis brachyodon'' Cope 1869* ''Pristis brayi'' Casier 1949* ''Pristis caheni'' Dartevelle and Casier 1959* ''Pristis contortus'' Dixon 1850* ''Pristis curvidens'' Leidy 1855* ''Pristis dubius'' Münster 1846* ''Pristis ensidens'' Leidy 1855* ''Pristis fajumensis'' Stromer 1905* ''Pristis hastingsiae'' Agassiz 1843* ''Pristis lanceolatus'' Jonet 1968* ''Pristis lathami'' Galeotti 1837* ''Pristis olbrechtsi'' Dartevelle and Casier 1959* ''Pristis pectinatus'' Latham 1794* ''Pristis pickeringi'' Case 1981* ''Pristis prosulcatus'' Stromer 1905Fossil rostal teeth of ''Pristis lathami'' from Khouribga (Morocco. )However, among this list are some species considered invalid by recent authorities and others now generally recognized as belonging in ''Anoxypristis''. Fossil ''Pristis'' range from the Late Paleocene to the Quaternary period. Fossils have been found all over the world.
References