PBDB Taxon

Basic info	Taxonomic history	Classification	Included Taxa
Morphology	Ecology and taphonomy	External Literature Search	Age range and collections

Metaxytherium medium

Mammalia - Sirenia - Dugongidae

Taxonomy

Hippopotamus medius was named by Desmarest (1822). Its type specimen is MNHN Fs 2706, a mandible (partial left mandible with M2-3), and it is a 3D body fossil. Its type locality is Baltringen, which is in a Burdigalian marine horizon in Germany.

It was recombined as Hippopotamus (Tetraprotodon) medius by Falconer and Cautley (1836); it was synonymized subjectively with Metaxytherium cordieri by Trouessart (1898); it was recombined as Metaxytherium medium by Hooijer (1952), Heal (1973), Fondi and Pacini (1974), Domning (1994), Domning (1996), Bianucci and Landini (2003), Domning (2008), Domning and Pervesler (2012), Voss (2014), Iliopoulos et al. (2022).

Sister species lacking formal opinion data

M. subappeninum

Synonyms

Trichechus molassicus was named by Bronn (1837). It is a 3D body fossil. Its type locality is Baltringen, which is in a Burdigalian marine horizon in Germany.

It was synonymized subjectively with Halitherium fossile by Scott (1873).
Metaxytherium petersi was named by Abel (1904) [Type specimen is now lost, probably destroyed during World War II (Domning, 1996). Type specimen is now lost, probably destroyed during World War II (Domning, 1996).]. Its type specimen is destroyed, a skeleton (skeleton lacking skull), and it is a 3D body fossil. Its type locality is Hainburg An Der Donau, which is in a Badenian marine sandstone in Austria.

It was recombined as Thalattosiren petersi by Sickenberg (1928), Domning (1996); it was synonymized subjectively with Metaxytherium medium by Domning and Pervesler (2012).
Haplosiren leganyii was named by Kretzoi (1951). Its type specimen is FIV 6001. Its type locality is Matrozollos, which is in a Tortonian marine horizon in Hungary. It is the type species of Haplosiren.

It was synonymized subjectively with Metaxytherium medium by Domning (1996).
Metaxytherium catalaunicum was named by Pilleri et al. (1989) [Villafranca del Penedes]. Its type specimen is 1210 Museum Comarcal, a skull, and it is not a trace fossil. Its type locality is Olerdola, which is in a Burdigalian/Langhian marine horizon in Spain.

It was synonymized subjectively with Metaxytherium medium by Domning (1996), Domning and Pervesler (2012).
Halicore cuvierii was named by de Christol (1832).

It was recombined as Halitherium cuvieri by Kaup (1840), Woodward (1885); it was recombined as Metaxytherium cuvierii by de Christol (1844); it was recombined as Manatus cuvieri by de Blainville (1844); it was recombined as Halianassa cuvieri by Bronn (1848); it was synonymized subjectively with Halitherium schinzi by Bronn (1853), Trouessart (1898); it was recombined as Metaxytherium cuvieri by Zittel (1925), Fondi and Pacini (1974); it was synonymized subjectively with Metaxytherium medium by Domning (1996), Domning and Pervesler (2012).
Hippopotamus intermedius was named by Holl (1829).

It was synonymized subjectively with Halitherium cordieri by Bronn (1853); it was synonymized subjectively with Metaxytherium medium by Domning (1996).
Metaxytherium cordieri was named by de Christol in de Blainville (1844).

It was recombined as Halianassa cordieri by Bronn (1848); it was recombined as Halitherium cordieri by Bronn (1853) and Peters (1867); it was synonymized subjectively with Metaxytherium medium by Domning (1996), Domning and Pervesler (2012).
Manatus fossilis was named by Holl (1829).

It was recombined as Halitherium fossile by Scott (1873), Woodward (1885), Lydekker (1887); it was recombined as Metaxytherium fossile by Deperet (1895); it was synonymized subjectively with Metaxytherium medium by Domning (1996).

Synonymy list

Year	Name and author
1822	Hippopotamus medius Desmarest pp. 388-389
1829	Hippopotamus intermedius Holl
1829	Manatus fossilis Holl p. 69
1832	Halicore cuvierii de Christol
1836	Hippopotamus (Tetraprotodon) medius Falconer and Cautley p. 51
1837	Trichechus molassicus Bronn p. 732
1840	Halitherium cuvieri Kaup
1844	Manatus cuvieri de Blainville p. 122
1844	Metaxytherium cuvierii de Christol p. 130
1844	Metaxytherium cordieri de Christol in de Blainville p. 130
1847	Manatus fossilis Gervais p. 221
1848	Halianassa cordieri Bronn p. 562
1848	Halianassa cuvieri Bronn p. 562
1853	Halitherium cordieri Bronn p. 787
1867	Halitherium cordieri Peters p. 309
1873	Halitherium fossile Scott p. 55
1885	Halitherium cuvieri Woodward p. 425
1885	Halitherium fossile Woodward p. 425
1887	Halitherium fossile Lydekker p. 6
1895	Metaxytherium fossile Deperet p. 409
1898	Metaxytherium cordieri Trouessart p. 1004
1904	Metaxytherium petersi Abel p. 15
1904	Metaxitherium cordieri Trouessart p. 750
1925	Metaxytherium cuvieri Zittel p. 265
1928	Thalattosiren petersi Sickenberg p. 294
1944	Metaxytherium petersi Zbyszewski
1951	Haplosiren leganyii Kretzoi p. 438
1952	Metaxytherium medium Hooijer p. 114
1973	Metaxytherium medium Heal p. 140
1974	Metaxytherium cuvieri Fondi and Pacini p. 45
1974	Metaxytherium medium Fondi and Pacini p. 45
1989	Metaxytherium catalaunicum Pilleri et al. p. 68 figs. Plates XXVIII-XXXIII
1994	Metaxytherium medium Domning p. 189
1996	Metaxytherium medium Domning p. 387
1996	Thalattosiren petersi Domning p. 388
2003	Metaxytherium medium Bianucci and Landini p. 567
2008	Metaxytherium medium Domning p. 528
2012	Metaxytherium medium Domning and Pervesler p. 136
2014	Metaxytherium medium Voss p. 91 figs. Figure 3
2022	Metaxytherium medium Iliopoulos et al. p. 398

Is something missing? Join the Paleobiology Database and enter the data

Rank	Name	Author
kingdom	Animalia	()
—	Bilateria
—	Eubilateria	Ax 1987
—	Deuterostomia
phylum	Chordata	Haeckel 1874
subphylum	Vertebrata
superclass	Gnathostomata
—	Osteichthyes	()
subclass	Sarcopterygii	()
subclass	Dipnotetrapodomorpha	(Nelson 2006)
subclass	Tetrapodomorpha	()
—	Tetrapoda
—	Reptiliomorpha
—	Anthracosauria
subclass	Amphibiosauria	Kuhn 1967
—	Cotylosauria	()
—	Amniota
subclass	Synapsida

Rank	Name	Author
—	Therapsida	()
infraorder	Cynodontia	()
—	Mammaliamorpha
—	Mammaliaformes
class	Mammalia
—	Cladotheria
—	Zatheria
subclass	Tribosphenida	()
subclass	Theria
—	Eutheria	()
—	Placentalia
—	Afrotheria	Stanhope et al. 1998
—	Tethytheria
order	Sirenia	()
family	Dugongidae
subfamily	Halitheriinae	()
genus	Metaxytherium
species	medium	()

If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.

†Metaxytherium medium Desmarest 1822

show all | hide all

Invalid names: Halitherium cuvieri de Christol 1832 [synonym], Haplosiren leganyii Kretzoi 1951 [synonym], Hippopotamus intermedius Holl 1829 [synonym], Manatus fossilis Holl 1829 [synonym], Metaxytherium catalaunicum Pilleri et al. 1989 [synonym], Metaxytherium cordieri de Christol in de Blainville 1844 [synonym], Metaxytherium petersi Abel 1904 [synonym]

Diagnosis

Reference	Diagnosis
D. P. Domning and P. Pervesler 2012	Metaxytherium differing from M. krahu- letzi by ventral extremity of jugal usually lying fully ventral to orbit [c. 85(2)]; differs from later European species (M. serresii,M. subapenninum) by having a tusk alveolus much less than half the length of the premaxillary symphysis [c. 140(0)]._