''Hoplitomeryx'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

extinct Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...

deer-like

ruminant Ruminants are herbivorous grazing or browsing artiodactyls belonging to the suborder Ruminantia that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through microb ...

s which lived on the former

Gargano Island Gargano () is a historical and geographical sub-region in the province of Foggia, Apulia, southeast Italy, consisting of a wide isolated mountain massif made of highland and several peaks and forming the backbone of a promontory projecting in ...

during the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

and the

Early Pliocene Early may refer to: Places in the United States * Early, Iowa, a city * Early, Texas, a city * Early Branch, a stream in Missouri * Early County, Georgia * Fort Early, Georgia, an early 19th century fort Music * Early B, stage name of Jamaican d ...

, now a

peninsula A peninsula is a landform that extends from a mainland and is only connected to land on one side. Peninsulas exist on each continent. The largest peninsula in the world is the Arabian Peninsula. Etymology The word ''peninsula'' derives , . T ...

on the east coast of

Southern Italy Southern Italy (, , or , ; ; ), also known as () or (; ; ; ), is a macroregion of Italy consisting of its southern Regions of Italy, regions. The term "" today mostly refers to the regions that are associated with the people, lands or cultu ...

. ''Hoplitomeryx'', also known as "prongdeer", had five horns and sabre-like upper canines similar to a modern

musk deer Musk deer can refer to any one, or all eight, of the species that make up ''Moschus'', the only extant genus of the family (biology), family Moschidae. Despite being commonly called deer, they are not true deer belonging to the family Cervidae, b ...

. Its fossilized remains were retrieved from the late 1960s onwards from reworked reddish, massive or crudely stratified silty-sandy clays (terrae rossae), which partially fill the paleo-karstic fissures in the

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

limestone substrate and that are on their turn overlain by

Late Pliocene Late or LATE may refer to: Everyday usage * Tardy, or late, not being on time * Late (or the late) may refer to a person who is dead Music * Late (The 77s album), ''Late'' (The 77s album), 2000 * Late (Alvin Batiste album), 1993 * Late!, a pseudo ...

Early Pleistocene The Early Pleistocene is an unofficial epoch (geology), sub-epoch in the international geologic timescale in chronostratigraphy, representing the earliest division of the Pleistocene Epoch within the ongoing Quaternary Period. It is currently esti ...

sediments of a subsequently marine, shallow water and terrigenous origin. In this way a buried paleo

karst Karst () is a topography formed from the dissolution of soluble carbonate rocks such as limestone and Dolomite (rock), dolomite. It is characterized by features like poljes above and drainage systems with sinkholes and caves underground. Ther ...

originated. The fauna from the paleokarst fillings is known as '' Mikrotia'' fauna after the endemic murid of the region (initially named "Microtia", with a c, but later corrected, because the genus ''

Microtia Microtia is a congenital deformity where the auricle (external ear) is underdeveloped. A completely undeveloped auricle is referred to as anotia. Because microtia and anotia have the same origin, it can be referred to as microtia-anotia. Micro ...

'' was already occupied). Later, after the regression and continentalization of the area, a second karstic cycle started in the late Early Pleistocene, the neokarst, which removed part of the paleokarst fill.

Description

''Hoplitomeryx'' was a deer-like

with a pair of pronged horns above each orbit and one central nasal horn. Hoplitomerycids are not the only horned

deer A deer (: deer) or true deer is a hoofed ruminant ungulate of the family Cervidae (informally the deer family). Cervidae is divided into subfamilies Cervinae (which includes, among others, muntjac, elk (wapiti), red deer, and fallow deer) ...

; before the appearance of antlered deer, members of the deer family commonly had horns. Another left-over of this stage is ''

Antilocapra ''Antilocapra'' is a genus of the family Antilocapridae, which contains only a single living species, the pronghorn ''(Antilocapra americana)''. Another species, the Pacific pronghorn, lived in California during the Late Pleistocene and survived ...

'' of North America, the only survivor of a once successful group related to

Giraffidae The Giraffidae are a family (biology), family of ruminant artiodactyl mammals that share a recent common ancestor with deer and bovids. This family, once a diverse group spread throughout Eurasia and Africa, presently comprises only two extant ge ...

. The diagnostic features of ''Hoplitomeryx'' are: one central nasal horn and a pair of pronged orbital horns, protruding canines, complete fusion of the navicocuboid with the

metatarsal The metatarsal bones or metatarsus (: metatarsi) are a group of five long bones in the midfoot, located between the tarsal bones (which form the heel and the ankle) and the phalanges ( toes). Lacking individual names, the metatarsal bones are ...

, distally closed metatarsal gully, a non-parallel-sided

astragalus Astragalus may refer to: * ''Astragalus'' (plant), a large genus of herbs and small shrubs *Astragalus (bone) The talus (; Latin for ankle or ankle bone; : tali), talus bone, astragalus (), or ankle bone is one of the group of foot bones known ...

, and an elongated

patella The patella (: patellae or patellas), also known as the kneecap, is a flat, rounded triangular bone which articulates with the femur (thigh bone) and covers and protects the anterior articular surface of the knee joint. The patella is found in m ...

Species

The ''Hoplitomeryx'' skeletal material forms a

heterogeneous Homogeneity and heterogeneity are concepts relating to the uniformity of a substance, process or image. A homogeneous feature is uniform in composition or character (i.e., color, shape, size, weight, height, distribution, texture, language, i ...

group, containing four size groups from tiny to huge; within the size groups different morphotypes may be present. All size groups share the same typical ''Hoplitomeryx'' features. The different size groups are equally distributed over the excavated fissures, and are therefore not to be considered chronotypes. The hypothesis of an

archipelago An archipelago ( ), sometimes called an island group or island chain, is a chain, cluster, or collection of islands. An archipelago may be in an ocean, a sea, or a smaller body of water. Example archipelagos include the Aegean Islands (the o ...

consisting of different islands each with its own morphotype cannot be confirmed so far. The tiny and small specimens show

insular dwarfism Insular dwarfism, a form of phyletic dwarfism, is the process and condition of large animals evolving or having a reduced body size when their population's range is limited to a small environment, primarily islands. This natural process is disti ...

, but this cannot be said for the medium and huge specimens. Hoplitomeryx matthei - skull

The situation with several co-existing morphotypes on an island is paralleled by '' Candiacervus'' (

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

Crete Crete ( ; , Modern Greek, Modern: , Ancient Greek, Ancient: ) is the largest and most populous of the Greek islands, the List of islands by area, 88th largest island in the world and the List of islands in the Mediterranean#By area, fifth la ...

Greece Greece, officially the Hellenic Republic, is a country in Southeast Europe. Located on the southern tip of the Balkan peninsula, it shares land borders with Albania to the northwest, North Macedonia and Bulgaria to the north, and Turkey to th ...

). Opinions about its

taxonomy image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme o ...

differ, and at present two models prevail: one

for eight morphotypes, or alternatively, two genera for five

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

. The second model is based upon limb proportions only, but these are invalid taxonomic features for island endemics, as they change under influence of environmental factors that differ from the mainland. Also in ''Hoplitomeryx'' the morphotypes differ in limb proportions, but here different ancestors are unlikely, because in that case they all ancestors must have shared the typical hoplitomerycid features. In '' Candiacervus'' as well as in ''Hoplitomeryx'', the largest species is as tall as an elk, but gracile and slender. The large variation is instead explained as an example of adaptive radiation, starting when the

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

ancestor colonized the island. The range of empty niches promoted its radiation into several trophic types, yielding a differentiation in ''Hoplitomeryx''. The shared lack of large mammalian

predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...

s and the limited amount of food in all niches promoted the development of derived features in all size groups (apomorphies).

Taxonomy

The affinities of ''Hoplitomeryx'' have long been contentious, due to its unique morphology not closely resembling any living ruminant group. Originally, they were considered to be relatives of Cervidae (deer). However, analysis of the horn cores show that they more closely resemble those of bovids (bovines, antelopes), an affinity also supported by their inner ear anatomy, which resembles those of bovids.

Notes

References

* De Giuli, C. & Torre, D. 1984a. Species interrelationships and evolution in the Pliocene endemic faunas of Apricena (Gargano Peninsula - Italy). Geobios, Mém. spécial, 8: 379–383. * De Giuli, C., Masini, F., Torre, D. & Boddi, V. 1986. Endemism and bio-chronological reconstructions: the Gargano case history. Bollettino della Società Paleontologica Italiana,25 (3): 267–276. Modena. * Dermitzakis, M. & De Vos, J. 1987. Faunal Succession and the Evolution of Mammals in Crete during the Pleistocene. Neues Jahrbuch Geologische und Paläontologische Abhandlungen 173, 3: 377–408. * De Vos, J. 1979. The endemic Pleistocene deer of Crete. Proceedings of the Koninklijke Nederlandse Akademie van Wetenschappen, Series B 82, 1: 59–90. * De Vos, J. & Van der Geer, A.A.E. 2002. Major patterns and processes in biodiversity: axonomic diversity on islands explained in terms of sympatric speciation. In: Waldren, B. & Ensenyat (eds.). World Islands in Prehistory, International Insular Investigations, V Deia International Conference of Prehistory. Bar International Series, 1095: 395–405. * Freudenthal, M. 1972: Deinogalerix koenigswaldi nov. gen., nov. spec., a giant insectivore from the Neogene of Italy. Scripta Geologica 14

(includes full text PDF) * Freudenthal, M. 1976. Rodent stratigraphy of some Miocene fissure fillings in Gargano (prov. Foggia, Italy). Scripta Geologica 37

(includes full text PDF) * Freudenthal, M. 1985. Cricetidae (Rodentia) from the Neogene of Gargano (Prov. of Foggia, Italy). Scripta Geologica 77

(includes full text PDF) * Leinders, J.J.M. 1984. Hoplitomerycidae fam. nov. (Ruminantia, Mammalia) from Neogene fissure fillings in Gargano (Italy); part 1: The cranial osteology of Hoplitomeryx gen. nov. and a discussion on the classification of pecoran families. Scripta Geologica 70: 1-51, 9 pl

(includes full text PDF) * Mazza, P. 1987. Prolagus apricenicus and Prolagus imperialis: two new Ochotonids (Lagomorpha, Mammalia) of the Gargano (Southern Italy). Bollettino della Società Paleontologica Italiana, 26 (3): 233–243. *MAZZA, P. P. A. and RUSTIONI, M. (2011), Five new species of Hoplitomeryx from the Neogene of Abruzzo and Apulia (central and southern Italy) with revision of the genus and of Hoplitomeryx matthei Leinders, 1983. Zoological Journal of the Linnean Society, 163: 1304–1333. * Parra, V., Loreau, M. & Jaeger, J.-J. 1999. Incisor size and community structure in rodents: two tests of the role of competition. Acta Oecologica, 20: 93–101. * Mazza P.P.A. 2015 Scontrone (central Italy), signs of a 9-million-year-old tragedy. Lethaia, 48: 387–404. * Mazza, P.P.A., Rossi M.A., Agostini S. (2015) Hoplitomeryx (Late Miocene, Italy), an example of giantism in insular ruminants. Journal of Mammalian Evolution 22: 271–277. * Mazza P. P. A., Rossi M.A., Rustioni M., Agostini S., Masini F. and Savorelli, A. (2016) Observations on the postcranial anatomy of Hoplitomeryx (Mammalia, Ruminantia, Hoplitomericidae) from the Miocene of the Apulia Platform (Italy). Palaeontographica, 307 (1-6): 105–147. * Van der Geer, A.A.E. 1999. On the astragalus of the Miocene endemic deer Hoplitomeryx from the Gargano (Italy). In: Reumer, J. & De Vos, J. (eds.). Elephants have a snorkel! Papers in honour of P.Y. Sondaar: 325–336. Deinsea 7. * Van der Geer, A.A.E. 2005. The postcranial of the deer Hoplitomeryx (Mio-Pliocene; Italy): another example of adaptive radiation on Eastern Mediterranean Islands. Monografies de la Societat d'Història Natural de les Balears 12: 325–336. * Van der Geer, A.A.E. 2005. Island ruminants and the evolution of parallel functional structures. In: Cregut, E. (Ed.): Les ongulés holarctiques du Pliocène et du Pléistocène. Actes Colloque international Avignon, 19-22 septembre. Quaternair, 2005 hors-série 2: 231–240. * Van der Geer, A.A.E. 2008. The effect of insularity on the Eastern Mediterranean early cervoid Hoplitomeryx: the study of the forelimb. Quaternary International, 182(1)145-159. * Van der Geer, A., Lyras, G., de Vos, J. & Dermitzakis M. 2010. Evolution of Island Mammals: Adaptation and Extinction of Placental Mammals on Islands. Oxford: Wiley-Blackwell Publishing.

External links

Research on Hoplitomeryx

Research on island faunas

Publications on Hoplitomeryx
{{Taxonbar, from=Q3786730 Prehistoric cervoids Miocene Artiodactyla Pliocene Artiodactyla Zanclean extinctions Neogene mammals of Europe Fossil taxa described in 1984 Prehistoric Artiodactyla genera