In Romania, studies on tardigrades were rather fragmentary and with a significant discontinuity in time (last 40 years). Even though during this period more than 150 taxa (species and subspecies) were reported for this region (Rudescu 1964), many of them are now considered as non-valid, have been synonymized, or require confirmation. In fact, in the light of modern taxonomy, only 127 tardigrades species are consider to be present in Romania (in 26 of 41 Romanian counties) (Ciobanu et al. 2014). Species from the genus Milnesium Doyère, 1840 are known from many localities throughout the world, from the Antarctic through tropical and temperate zones to the Arctic regions (e.g. Tumanov 2006; Kaczmarek et al. 2012a, 2012b; Michalczyk et al. 2012a). Since the genus was recently re-described (Michalczyk et al. 2012a, 2012b) new records and species have been reported from various localities (e.g. Kaczmarek et al. 2012a; Meyer et al. 2013; Zawierucha et al. 2014; Ciobanu et al. 2014). Taking into consideration that some morphological characters were omitted in older records of Milnesium specimens, all such records should be verified (Michalczyk et al. 2012a, 2012b). Until now in Romania only three Milnesium species have been reported: Milnesium tardigradum sensu lato Doyère, 1840, Milnesium granulatum (Ramazzotti, 1962) and Milnesium asiaticum Tumanov, 2006, but all early records of the first species should be verified (Michalczyk et al. 2012a, 2012b; Ciobanu et al. 2014). In this paper a new species of the genus Milnesium is described and illustrated.

In a lichen sample collected by the first author in Bârlad town in July, 2013, 53 individuals and two exuvia (with 16 eggs) of the new species were found. Additionally, 55 specimens of Ramazzottius oberhaeuseri (Doyère, 1840) were found in the same sample, including 9 specimens in simplex stage and 9 eggs.

All specimens were extracted according to Dastych (1980, 1985) and mounted on microscope slides in Hoyer’s medium. Observations, measurements and photomicrographs were taken using Phase Contrast Microscopy (PCM) (Olympus BX41 with digital camera ARTCAM-300Mi). All measurements (determined with QuickPhoto Camera 2.3) are given in micrometers [μm].

Body length was measured from the mouth to the end of the body excluding the hind legs. The buccal tube and claws characteristics were measured according to Tumanov (2006) and Michalczyk et al. (2012a). Subsequently, claw configuration is described according to Michalczyk et al. (2012a, 2012b). Other morphometric data were calculated using the pt ratio: the ratio of the length of a given structure to the length of the buccal tube, expressed as a percentage (Pilato 1981). The pt values are always provided in italics in order to differentiate them from length values.

Characteristics and measurements of the species used in the differential diagnosis are given according to the original descriptions (Ramazzotti 1962; Pilato et al. 2002; Kaczmarek et al. 2004; Tumanov 2006; Kaczmarek and Michalczyk 2007; Wallendorf and Miller 2009; Kaczmarek et al. 2012a; Meyer et al. 2013) or are based on direct examination of type material (holotype and paratypes of Milnesium beasleyi Kaczmarek et al. 2012a). Ramazzottius specimens were verified and identified using the key to the World Tardigrada (Ramazzotti and Maucci 1983), a more modern key to the genus Ramazzottius (Biserov 1998), and remarks discussed by Pilato et al. (2013).

Morphometric data were handled using the ''Apochela'' ver. 1.1 template available from the Tardigrada Register (Michalczyk and Kaczmarek 2013). Raw data underlying the description of Milnesium berladnicorum sp. n. are deposited in the Tardigrada Register under http://www.tardigrada.net/register/0014.htm

Until 1990, the genus Milnesium Doyère, 1840 was considered as monotypic with only one described cosmopolitan species, Milnesium tardigradum Doyère, 1840. In 1990, Binda and Pilato described a second species, Milnesium brachyungue from Chile. Later, additional species in the genus Milnesium were described sporadically up to 2006 when Tumanov published the first, but partial, revision of the genus Milnesium and described five new species (Tumanov 2006). In 2012, the genus Milnesium was redescribed in more detail by Michalczyk et al. (2012a, 2012b), and the nominal species Milnesium tardigradum tardigradum sensu stricto Doyère, 1840 obtained a clear and definitive diagnosis.

At present the genus Milnesium consists of 21 species and one subspecies (Degma et al. 2014), which have been divided into two groups (based on the presence/absence of a sculptured cuticle): tardigradum and granulatum (Michalczyk et al. 2012a, 2012b). Due to the sculptured cuticle, Milnesium berladnicorum sp. n. belongs to the granulatum group. Including the new species, the granulatum group now consists of eight species: Milnesium alabamae Wallendorf and Miller, 2009 (from USA), Milnesium berladnicorum sp. n. (from Romania), Milnesium granulatum (Ramazzotti, 1962) (from Chile, Italy, Romania and USA), Milnesium katarzynae Kaczmarek et al., 2004 (from Costa Rica and China), Milnesium krzysztofi Kaczmarek and Michalczyk, 2007 (Costa Rica and Peru), Milnesium reticulatum Pilato et al., 2002 (Seychelles), Milnesium beasleyi Kaczmarek et al., 2012 (Turkey) and Milnesium lagniappe Meyer et al., 2013 (USA) (Ramazzotti 1962; Pilato et al. 2002; Kaczmarek et al. 2004; Kaczmarek and Michalczyk 2007; Wallendorf and Miller 2009; Kaczmarek et al. 2012; Michalczyk et al. 2012a, 2012b; Meyer et al. 2013; Kaczmarek et al. 2014; Bartels et al. 2014). Thus, granulatum group is equivalent to ca. 39% of all known Milnesium taxa and the “sculptured species” are distributed around the World.

According to Rudescu (1964), Milnesium tardigradum sensu lato Doyère, 1840 was firstly reported in Romanian territory by Botezat (1903) in the area of Suceava County (Austro-Hungarian Empire at the time). Later, it was reported numerous times at different Romanian localities by: Rodewald (1936), Iharos (1937, 1940, 1962), Péterfi (1956), Botoşăneanu and Negrea (1961), and Rudescu (1964). However, based on modern literature, all these records should be considered as dubious and need verification (Michalczyk et al. 2012a, 2012b). This is now even more necessary due to the discovery in 2014 of two other Milnesium species in Romania (Ciobanu et al. 2014): a) Milnesium asiaticum Tumanov, 2006, previously known only from three localities in Kyrgyzstan (Tumanov 2006), Spitsbergen (Kaczmarek et al. 2012b) and Estonia (Zawierucha et al. 2014); and b) Milnesium granulatum (Ramazzotti, 1962) previously known only from three localities in Chile, Italy and USA (McInnes 1994; Bartels et al. 2014) (see map above).

Including the new species described here, the total number of valid tardigrade taxa recorded in Romania is 128, with three valid Milnesium species (not including Milnesium tardigradum tardigradum sensu stricto, which requires confirmation of presence in Romania).

The authors want to thank Prof. Diane Nelson of East Tennessee State University for help in improving of the English in the manuscript. We are also grateful to anonymous

reviewers for valuable remarks. This work was partially funded by the Prometeo Project of the Secretariat for Higher Education, Science, Technology and Innovation of the Republic of Ecuador. Studies have been partially conducted in the framework of activities of BARg (Biodiversity and Astrobiology Research group) at the Adam Mickiewicz University in Poznań, Poland.