''Armadillidium pieperi'' is a

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

woodlouse A woodlouse (plural woodlice) is an isopod crustacean from the polyphyleticThe current consensus is that Oniscidea is actually triphyletic suborder Oniscidea within the order Isopoda. They get their name from often being found in old wood. ...

endemic to

Greece Greece,, or , romanized: ', officially the Hellenic Republic, is a country in Southeast Europe. It is situated on the southern tip of the Balkans, and is located at the crossroads of Europe, Asia, and Africa. Greece shares land borders with ...

. It is a relatively medium-sized species that probably belongs to the so-called "''

Armadillidium fossuligerum ''Armadillidium'' () is a genus of the small terrestrial crustacean known as the woodlouse. ''Armadillidium'' are also commonly known as pill woodlice, leg pebbles, pill bugs, roly-poly, or potato bugs, and are often confused with pill millipedes ...

'' complex".

Taxonomy

''Armadilliidum pieperi'' was described as a distinct species of

Armadillidium ''Armadillidium'' () is a genus of the small terrestrial crustacean known as the woodlouse. ''Armadillidium'' are also commonly known as pill woodlice, leg pebbles, pill bugs, roly-poly, or potato bugs, and are often confused with pill millipedes ...

in 2008, based on specimens collected as far back as 1980. The species is also thought to belong to the "''Armadillidium fossuligerum'' complex", a group of 4 species ('' A. jerenntrupi'', ''A. fossuligerum''

sensu lato ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular co ...

, '' A. petralonense'' and ''A. pieperi'') that occur in the southern part of the

Balkan Peninsula The Balkans ( ), also known as the Balkan Peninsula, is a geographical area in southeastern Europe with various geographical and historical definitions. The region takes its name from the Balkan Mountains that stretch throughout the who ...

(mainly Greece and the adjacent areas of

North Macedonia North Macedonia, ; sq, Maqedonia e Veriut, (Macedonia before February 2019), officially the Republic of North Macedonia,, is a country in Southeast Europe. It gained independence in 1991 as one of the successor states of Socialist Feder ...

and

Bulgaria Bulgaria (; bg, България, Bǎlgariya), officially the Republic of Bulgaria,, ) is a country in Southeast Europe. It is situated on the eastern flank of the Balkans, and is bordered by Romania to the north, Serbia and North Macedon ...

). It can be separated from the first two species by the shape of the

telson The telson () is the posterior-most division of the body of an arthropod. Depending on the definition, the telson is either considered to be the final segment of the arthropod body, or an additional division that is not a true segment on accou ...

(pointed instead of

truncate In mathematics and computer science, truncation is limiting the number of digits right of the decimal point. Truncation and floor function Truncation of positive real numbers can be done using the floor function. Given a number x \in \mathbb ...

) and from the

allopatric Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from ...

, but very similar, ''A. petralonense'' by the ventral shape of the ischium of the seventh

pereiopod The decapod (crustaceans such as a crab, lobster, shrimp or prawn) is made up of 20 body segments grouped into two main body parts: the cephalothorax and the pleon (abdomen). Each segment may possess one pair of appendages, although in various g ...

of the male (strongly concave in ''A. pieperi'' vs straight in ''A. petralonense'').

Description

''Armadillidium petralonense'' is a medium-sized species, reaching maximum dimensions of about 17 x 6.7 mm. Its

tergites A ''tergum'' (Latin for "the back"; plural ''terga'', associated adjective tergal) is the dorsal ('upper') portion of an arthropod segment other than the head. The anterior edge is called the 'base' and posterior edge is called the 'apex' or 'mar ...

are faintly tuberculated and have a uniform greyish-brown coloration with lighter epimera. Like its sister species, ''A. petralonense'', the frontal shield surpasses the anterior edge of the head, has a completely rounded upper margin and lacks lateral angles. Also, the head itself has a distinct groove in the middle, immediately behind the frontal shield. The secondary antennae have trapezoidal lobes and the second article of the

flagellum A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have f ...

is slightly longer than the first. The hind margins of the first pair of epimera are obtuse-angled. The telson is as wide as long, has nearly straight sides and a rounded tip. Concerning the sexual characters of the male, the first pereiopod has a few short spines on the carpus and the ischium of the seventh pereiopod is ventrally concave and decorated with a hair field at its apical part. The posterior lobe of the exopodite of the first

pleopod The decapod ( crustaceans such as a crab, lobster, shrimp or prawn) is made up of 20 body segments grouped into two main body parts: the cephalothorax and the pleon (abdomen). Each segment may possess one pair of appendages, although in various ...

is triangular and the apex of the endopodite is straight .

Distribution

''Armadillidium pieperi'' is endemic to the Greek regional unit of

Chalkidiki Chalkidiki (; el, Χαλκιδική , also spelled Halkidiki, is a peninsula and regional unit of Greece, part of the region of Central Macedonia, in the geographic region of Macedonia in Northern Greece. The autonomous Mount Athos region co ...

in the region of

Central Macedonia Central Macedonia ( el, Κεντρική Μακεδονία, Kentrikí Makedonía, ) is one of the thirteen administrative regions of Greece, consisting of the central part of the geographical and historical region of Macedonia. With a populat ...

. Specifically, until now, specimens have been collected only from the southernmost regions of the two

peninsula A peninsula (; ) is a landform that extends from a mainland and is surrounded by water on most, but not all of its borders. A peninsula is also sometimes defined as a piece of land bordered by water on three of its sides. Peninsulas exist on all ...

municipalities A municipality is usually a single administrative division having corporate status and powers of self-government or jurisdiction as granted by national and regional laws to which it is subordinate. The term ''municipality'' may also mean the go ...

of Chalkidiki, namely Kassandra and

Sithonia Sithonia ( el, Σιθωνία), also known as Longos, is a peninsula of Chalkidiki, which itself is located on a larger peninsula within Greece. The Kassandra Peninsula lies to the west of Sithonia and the Mount Athos peninsula to the east. Sithon ...

References

{{Taxonbar, from=Q107096598 Woodlice Woodlice of Europe Crustaceans described in 2008