47-462: See text Gomphotherium ( / ˌ ɡ ɒ m f ə ˈ θ ɪər i əm / ; "nail beast" for its double set of straight tusks) is an extinct genus of gomphothere proboscidean from the Neogene of Eurasia, Africa and North America. It is the most diverse genus of gompothere, with over a dozen valid species. The genus is probably paraphyletic . Most species of Gomphotherium were similar in size to
94-700: A paraphyletic Gomphotheriidae and Gomphotherium . Phiomia Mammutidae (mastodons) Eritreum Gomphotherium annectens Choerolophodontidae Amebelodontidae (shovel tuskers) Gomphotherium angustidens Gomphotherium steinheimense Elephantoidea ("tetralophodont gomphotheres", Elephantidae) Gomphotherium sylvaticum Gomphotherium inopinatum Gomphotherium browni Gomphotherium tassyi Gomphotherium productum + American gomphotheres [REDACTED] Gomphothere Gomphotheres are an extinct group of proboscideans related to modern elephants . First appearing in Africa during
141-541: A paraphyletic Gomphotheriidae. Mammutidae (mastodons) Eritreum Gomphotherium annectens Choerolophodontidae Amebelodontidae (shovel tuskers) Gomphotherium angustidens Gomphotherium steinheimense Elephantoidea ("tetralophodont gomphotheres", Elephantidae) Gomphotherium sylvaticum Gomphotherium inopinatum Gomphotherium browni Gomphotherium tassyi Gomphotherium productum + American gomphotheres Gomphotheres are generally supposed to have been flexible feeders, with
188-479: A "single common ancestor" organism. Paraphyly is common in speciation , whereby a mother species (a paraspecies ) gives rise to a daughter species without itself becoming extinct. Research indicates as many as 20 percent of all animal species and between 20 and 50 percent of plant species are paraphyletic. Accounting for these facts, some taxonomists argue that paraphyly is a trait of nature that should be acknowledged at higher taxonomic levels. Cladists advocate
235-592: A cell nucleus, a plesiomorphy ) from its excluded descendants. Also, some systematists recognize paraphyletic groups as being involved in evolutionary transitions, the development of the first tetrapods from their ancestors for example. Any name given to these hypothetical ancestors to distinguish them from tetrapods—"fish", for example—necessarily picks out a paraphyletic group, because the descendant tetrapods are not included. Other systematists consider reification of paraphyletic groups to obscure inferred patterns of evolutionary history. The term " evolutionary grade "
282-423: A convergent process that occurred multiple times among gomphotheres, as well as other members of Elephantimorpha. The incisors and long lower jaws of primitive gomphotheres were likely used for cutting vegetation, while brevirostrine gomphotheres relied on their trunks to acquire food similar to modern elephants. The limb bones of gomphotheres like those of mammutids are generally more robust than elephantids, with
329-419: A group of dinosaurs (part of Diapsida ), both of which are "reptiles". Osteichthyes , bony fish, are paraphyletic when circumscribed to include only Actinopterygii (ray-finned fish) and Sarcopterygii (lungfish, etc.), and to exclude tetrapods ; more recently, Osteichthyes is treated as a clade, including the tetrapods. The " wasps " are paraphyletic, consisting of the narrow-waisted Apocrita without
376-439: A kind of lizard). Put another way, viviparity is a synapomorphy for Theria within mammals, and an autapomorphy for Eulamprus tympanum (or perhaps a synapomorphy, if other Eulamprus species are also viviparous). Groupings based on independently-developed traits such as these examples of viviparity represent examples of polyphyly , not paraphyly. The following list recapitulates a number of paraphyletic groups proposed in
423-506: A more inclusive clade, it often makes sense to study the paraphyletic group that remains without considering the larger clade. For example, the Neogene evolution of the Artiodactyla (even-toed ungulates, like deer, cows, pigs and hippopotamuses - Cervidae , Bovidae , Suidae and Hippopotamidae , the families that contain these various artiodactyls, are all monophyletic groups) has taken place in environments so different from that of
470-424: A phylogenetic species concept that does not consider species to exhibit the properties of monophyly or paraphyly, concepts under that perspective which apply only to groups of species. They consider Zander's extension of the "paraphyletic species" argument to higher taxa to represent a category error When the appearance of significant traits has led a subclade on an evolutionary path very divergent from that of
517-500: A role in their extinction. [REDACTED] Paraphyly Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic with respect to the excluded subgroups. In contrast, a monophyletic grouping (a clade ) includes a common ancestor and all of its descendants. The terms are commonly used in phylogenetics (a subfield of biology ) and in
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#1732782576993564-439: Is a monophyletic group from which one or more subsidiary clades (monophyletic groups) are excluded to form a separate group. Philosopher of science Marc Ereshefsky has argued that paraphyletic taxa are the result of anagenesis in the excluded group or groups. A cladistic approach normally does not grant paraphyletic assemblages the status of "groups", nor does it reify them with explanations, as in cladistics they are not seen as
611-433: Is allowed as a synonym of Magnoliopsida. Phylogenetic analysis indicates that the monocots are a development from a dicot ancestor. Excluding monocots from the dicots makes the latter a paraphyletic group. Among animals, several familiar groups are not, in fact, clades. The order Artiodactyla ( even-toed ungulates ) as traditionally defined is paraphyletic because it excludes Cetaceans (whales, dolphins, etc.). Under
658-442: Is paraphyletic with respect to birds . Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor except for birds. Other commonly recognized paraphyletic groups include fish , monkeys , and lizards . The term paraphyly , or paraphyletic , derives from the two Ancient Greek words παρά ( pará ), meaning "beside, near", and φῦλον ( phûlon ), meaning "genus, species", and refers to
705-482: Is sometimes used for paraphyletic groups. Moreover, the concepts of monophyly , paraphyly, and polyphyly have been used in deducing key genes for barcoding of diverse group of species. Current phylogenetic hypotheses of tetrapod relationships imply that viviparity , the production of offspring without the external laying of a fertilized egg, developed independently in the lineages that led to humans ( Homo sapiens ) and southern water skinks ( Eulampus tympanum ,
752-525: Is suggested to be the ancestor of later New World gomphothere genera. "Trilophodont gomphotheres" dramatically declined during the Late Miocene, likely due to the increasing C 4 grass-dominated habitats, while during the Late Miocene "tetralophodont gomphotheres" were abundant and widespread in Eurasia, where they represented the dominant group of proboscideans. All trilophodont gomphotheres, with
799-955: The Asian elephant , with G. productum (known from a 35-year-old male) measuring 2.51 m (8 ft 3 in) tall and weighing 4.6 t (4.5 long tons; 5.1 short tons). The largest species G. steinheimense , known from a complete 37-year-old male found in Mühldorf , Germany, measured up to 3.17 m (10.4 ft) tall and weighed 6.7 t (6.6 long tons; 7.4 short tons). Gomphotherium , like most basal elephantimorphs , had an elongated lower jaw which bore tusks. Species of Gomphotherium are defined by their conservative molar morphology, which includes "trilophed intermediate molars, third molars with three to four loph(id)s, and pretrite half-loph(id)s typically with anterior and posterior accessory conules that form trefoil-patterned enamel loops with wear (simple molar crowns with no accessory conules on
846-514: The Cetacea (whales, dolphins, and porpoises) that the Artiodactyla are often studied in isolation even though the cetaceans are a descendant group. The prokaryote group is another example; it is paraphyletic because it is composed of two Domains (Eubacteria and Archaea) and excludes (the eukaryotes ). It is very useful because it has a clearly defined and significant distinction (absence of
893-581: The ICN ) abandoned consideration of bacterial nomenclature in 1975; currently, prokaryotic nomenclature is regulated under the ICNB with a starting date of 1 January 1980 (in contrast to a 1753 start date under the ICBN/ICN). Among plants, dicotyledons (in the traditional sense) are paraphyletic because the group excludes monocotyledons . "Dicotyledon" has not been used as a botanic classification for decades, but
940-709: The Oligocene , they dispersed into Eurasia and North America during the Miocene and arrived in South America during the Pleistocene as part of the Great American Interchange . Gomphotheres are a paraphyletic group ancestral to Elephantidae , which contains modern elephants, as well as Stegodontidae . While most famous forms such as Gomphotherium had long lower jaws with tusks,
987-719: The Pleistocene , around or after 2.5 million years ago as part of the Great American Biotic Interchange due to the formation of the Isthmus of Panama , becoming widespread across the continent. The last gomphothere native to Europe, Anancus arvernensis became extinct during the Early Pleistocene, around 1.6–2 million years ago Sinomastodon became extinct at the end of the Early Pleistocene , around 800,000 years ago. From
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#17327825769931034-467: The ancestral condition for the group, some later members developed shortened (brevirostrine) lower jaws with either vestigial or no lower tusks and outlasted the long-jawed gomphotheres. This change made them look very similar to modern elephants, an example of parallel evolution . During the Pliocene and Early Pleistocene , the diversity of gomphotheres declined, ultimately becoming extinct outside of
1081-660: The ants and bees . The sawflies ( Symphyta ) are similarly paraphyletic, forming all of the Hymenoptera except for the Apocrita, a clade deep within the sawfly tree. Crustaceans are not a clade because the Hexapoda (insects) are excluded. The modern clade that spans all of them is the Tetraconata . One of the goals of modern taxonomy over the past fifty years has been to eliminate paraphyletic "groups", such as
1128-448: The tree model of historical linguistics . Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies . If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term received currency during the debates of the 1960s and 1970s accompanying the rise of cladistics , having been coined by zoologist Willi Hennig to apply to well-known taxa like Reptilia ( reptiles ), which
1175-683: The Americas. The last two genera, Cuvieronius ranging southern North America to western South America, and Notiomastodon ranging over most of South America, continued to exist until the end of the Pleistocene around 12,000 years ago, when they became extinct along with many other megafauna species following the arrival of humans . The name "gomphothere" comes from Ancient Greek γόμφος ( gómphos ), "peg, pin; wedge; joint" plus θηρίον ( theríon ), "beast". Gomphotheres differed from elephants in their tooth structure, particularly
1222-653: The Pliocene and Pleistocene epochs. In southern North America, Central America and South America, gomphotheres did not become extinct until shortly after the arrival of humans to the Americas, approximately 12,000 years ago, as part of the Late Pleistocene megafauna extinctions of most large mammals across the Americas. Bones of the last gomphothere genera, Cuvieronius and Notiomastodon, dating to shortly before their extinction have been found associated with human artifacts, suggesting that hunting may have played
1269-495: The actual products of evolutionary events. A group whose identifying features evolved convergently in two or more lineages is polyphyletic (Greek πολύς [ polys ], "many"). More broadly, any taxon that is not paraphyletic or monophyletic can be called polyphyletic. Empirically, the distinction between polyphyletic groups and paraphyletic groups is rather arbitrary, since the character states of common ancestors are inferences, not observations. These terms were developed during
1316-647: The ancestor of later gomphothere genera, including the "tetralophodont gomphotheres" such as Tetralophodon which are probably ancestral to stegodontids and elephantids . Gomphotherium first arrived in North America during the mid-Miocene, approximately 16-15 million years ago, and is suggested to be ancestral to later New World gomphothere genera, such as Cuvieronius , Stegomastodon and Rhynchotherium . Asian populations of Gomphotherium are suggested to have been ancestral to Sinomastodon . The last European species of Gomphotherium became extinct at
1363-997: The beginning of the Late Miocene, around the start of MN9 , approximately 10 million years ago. The last Gomphotherium species disappeared from North America at the beginning of the Pliocene, approximately 5 million years ago. Over a dozen species of Gomphotherium are considered valid, with over 30 junior synonyms proposed for these taxa. Phylogeny after Wang et al. , 2017 Phiomia serridens Eritreum melakeghebrekristosi Gomphotherium sp. (Mwiti) Gomphotherium hannibali Gomphotherium annectens Gomphotherium cooperi Gomphotherium sylvaticum Gomphotherium libycum Gomphotherium pygmaeus Gomphotherium inopinatum Gomphotherium mongoliense Gomphotherium angustidens ( s. s. ) Gomphotherium connexum Gomphotherium subtapiroideum Gomphotherium tassyi Gomphotherium wimani Gomphotherium browni Gomphotherium productum Gomphotherium steinheimense Cladogram of Elephantiformes after Li et al. 2023, showing
1410-572: The chewing surfaces on the molar teeth. The teeth are considered to be bunodont , that is, having rounded cusps. They are thought to have chewed differently from modern elephants, using an oblique movement (combining back to front and side to side motion) over the teeth rather than the proal movement (a forwards stroke from the back to the front of the lower jaws) used by modern elephants and stegodontids. Like modern elephants and other members of Elephantimorpha , gomphotheres had horizontal tooth replacement, where teeth would progressively migrate towards
1457-490: The debates of the 1960s and 1970s accompanying the rise of cladistics . Paraphyletic groupings are considered problematic by many taxonomists, as it is not possible to talk precisely about their phylogenetic relationships, their characteristic traits and literal extinction. Related terms are stem group , chronospecies , budding cladogenesis, anagenesis, or 'grade' groupings. Paraphyletic groups are often relics from outdated hypotheses of phylogenic relationships from before
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1504-478: The descendants of a unique common ancestor. By comparison, the term polyphyly , or polyphyletic , uses the Ancient Greek prefix πολύς ( polús ), meaning "many, a lot of", and refers to the fact that a polyphyletic group includes organisms arising from multiple ancestral sources. Groups that include all the descendants of a common ancestor are said to be monophyletic . A paraphyletic group
1551-450: The examples given here, from formal classifications. Species have a special status in systematics as being an observable feature of nature itself and as the basic unit of classification. Some articulations of the phylogenetic species concept require species to be monophyletic, but paraphyletic species are common in nature, to the extent that they do not have a single common ancestor. Indeed, for sexually reproducing taxa, no species has
1598-540: The exception of the Asian Sinomastodon , became extinct in Eurasia by the beginning of the Pliocene , along with the global extinction of the "shovel tusker" amebelodontids. The last gomphotheres in Africa, represented by the "tetralophodont gomphothere" genus Anancus , became extinct around the end of the Pliocene and beginning of the Pleistocene. The New World gomphothere genera Notiomastodon and Cuvieronius dispersed into South America during
1645-456: The front of the jaws before they were taken place by more posterior teeth. Unlike modern elephants, many gomphotheres retained permanent premolar teeth though they were absent in some gomphothere genera. Earlier gomphotheres had lower jaws with an elongate mandibular symphysis and lower tusks, the primitive condition for members of Elephantimorpha . Later members developed shortened (brevirostrine) lower jaws and/or vestigial or no lower tusks,
1692-488: The group which contains modern elephants, as well as Stegodontidae . While the North American long jawed proboscideans Gnathabelodon , Eubelodon and Megabelodon been assigned to Gomphotheriidae in some studies other studies suggest that they should be assigned to Amebelodontidae ( Eubelodon, Megabelodon ) or Choerolophodontidae ( Gnathabelodon ). Cladogram of Elephantimorpha after Li et al. 2023, showing
1739-526: The late Oligocene -early Miocene . The oldest remains of Gomphotherium are known from Africa, dating to approximately 19.5 million years ago . Gomphotherium migrated into Eurasia across the " Gomphotherium land bridge " approximately 19 million years ago. Gomphotherium underwent rapid evolution after its arrival in Eurasia, reaching its peak diversity during the Early-Middle Miocene. Gomphotherium has been posited to be paraphyletic and
1786-500: The latter half of the Early Pleistocene onwards, gomphotheres were extirpated from most of North America, likely due to competition with mammoths and mastodons . The extinction of gomphotheres in Afro-Eurasia has generally been supposed to be the result the expansion of Elephantidae and Stegodon . The morphology of elephantid molars being more efficient than gomphotheres in consuming grass, which became more abundant during
1833-755: The legs also tending to be proportionally shorter. Their bodies also tend to be more proportionally elongate than those of living elephants. "Gomphotheres" are assigned to their own family, Gomphotheriidae, but are widely agreed to be a paraphyletic group. The families Choerolophodontidae and Amebelodontidae (the latter of which includes "shovel tuskers" with flattened lower tusks like Platybelodon ) are sometimes considered gomphotheres sensu lato, though some authors argue that Amebelodontidae should be sunk into Gomphotheriidae. Gomphotheres are divided into two informal groups, "trilophodont gomphotheres", and "tetralophodont gomphotheres". "Tetralophodont gomphotheres" are distinguished from "trilophodont gomphotheres" by
1880-622: The literature, and provides the corresponding monophyletic taxa. The concept of paraphyly has also been applied to historical linguistics , where the methods of cladistics have found some utility in comparing languages. For instance, the Formosan languages form a paraphyletic group of the Austronesian languages because they consist of the nine branches of the Austronesian family that are not Malayo-Polynesian and are restricted to
1927-757: The mid- Oligocene , with remains from the Shumaysi Formation in Saudi Arabia dating to around 29-28 million years ago. Gomphotheres were uncommon in Afro-Arabia during the Oligocene. Gomphotheres arrived in Eurasia after the connection of Afro-Arabia and Eurasia during the Early Miocene around 19 million years ago, in what is termed the " Proboscidean Datum Event ". Gomphotherium arrived in North America around 16 million years ago, and
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1974-472: The posttrite side of the crown)". Most species of Gomphotherium are inferred to have been browsers or mixed feeders, but specimens of G . steinheimense from China are suggested to have been grazers . Oxygen and carbon isotopes from G. productum enamel unearthed in the Port of Entry Pit, Oklahoma reveal it fed predominantly on C 3 plants year-round. Gomphotherium likely originated in Africa during
2021-430: The presence of four ridges on the fourth premolar and on the first and second molars, rather than the three present in trilophodont gomphotheres. Some authors choose to exclude "tetralophodont gomphotheres" from Gomphotheriidae, and instead assign them to the group Elephantoidea . "Tetralophodont gomphotheres" are thought to have evolved from "trilophodont gomphotheres", and are suggested to be ancestral to Elephantidae ,
2068-696: The ranks of the ICZN Code , the two taxa are separate orders. Molecular studies, however, have shown that the Cetacea descend from artiodactyl ancestors, although the precise phylogeny within the order remains uncertain. Without the Cetaceans the Artiodactyls are paraphyletic. The class Reptilia is paraphyletic because it excludes birds (class Aves ). Under a traditional classification, these two taxa are separate classes. However birds are sister taxon to
2115-567: The rise of cladistics. The prokaryotes (single-celled life forms without cell nuclei) are a paraphyletic grouping, because they exclude the eukaryotes , a descendant group. Bacteria and Archaea are prokaryotes, but archaea and eukaryotes share a common ancestor that is not ancestral to the bacteria. The prokaryote/eukaryote distinction was proposed by Edouard Chatton in 1937 and was generally accepted after being adopted by Roger Stanier and C.B. van Niel in 1962. The botanical code (the ICBN, now
2162-405: The situation in which one or several monophyletic subgroups of organisms (e.g., genera, species) are left apart from all other descendants of a unique common ancestor. Conversely, the term monophyly , or monophyletic , builds on the Ancient Greek prefix μόνος ( mónos ), meaning "alone, only, unique", and refers to the fact that a monophyletic group includes organisms consisting of all
2209-495: The various species having differing browsing , mixed feeding and grazing diets, with the dietary preference of individual species and populations being shaped by local factors such as climatic conditions and competition. Analysis of the tusks of a male Notiomastodon individual suggest that it underwent musth , similar to modern elephants. Notiomastiodon is also suggested to have lived in social family groups, like modern elephants. Gomphotheres originated in Afro-Arabia during
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