Algorachelus parva (Haas, 1978a)
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publication ID |
https://doi.org/10.26879/1398 |
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persistent identifier |
https://treatment.plazi.org/id/AD69E14D-1B66-984A-5C42-F998FDFCF9F9 |
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treatment provided by |
Felipe |
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scientific name |
Algorachelus parva (Haas, 1978a) |
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Algorachelus parva (Haas, 1978a)
Figures 1-3 View FIGURE 1 View FIGURE 2 View FIGURE 3
1978b Podocnemis parva ; Haas, p. 169, 172, 175.
1978b Podocnemis judaea ; Haas, p. 169-175, figures 1-4.
1988 Bothremys parva ; Antunes and Broin, p. 163, 165, 174, 177, 179, 182, 184-185.
1988 Bothremys parva ; Broin, p. 134.
1998 Bothremys parva ; Lapparent de Broin and Werner, p. 164, 169.
2005 ‘Podocnemis’ parva ; Zalmout, Mustafa, and Wilson, p. 158, 160, 171.
2005 ‘ Podocnemis’ judaea ; Zalmout, Mustafa, and Wilson, p. 158, 160, 171.
2006 ‘ Podocnemis’ judea; Gaffney, Tong, and Meylan, p. 110.
2006 ‘ Podocnemis’ parva ; Gaffney, Tong, and Meylan, p. 110, 569, 683.
2012 ‘ Podocnemis parva’; Rabi, Tong, and Botfalvai, p. 11.
2012 ‘ Podocnemis judea’; Rabi, Tong, and Botfalvai, p. 11.
2013 ‘Podocnemis’ parva ; Georgalis, Velitzelos, Velitzelos, and Kear, p. 284.
2013 ‘Podocnemis’ judea; Georgalis, Velitzelos, Velitzelos, and Kear, p. 284.
2016 ‘Podocnemis’ parva ; Pérez-García, p.
710, 720-722, 726, 728.
2016 ‘Podocnemis’ parva ; Joyce, Lyson, and Kirkland, p. 6, 15-16.
2017b Algorachelus parva ; Pérez-García, Antunes, Barroso-Barcenilla, Callapez, Segura, Soares, and Torices, p. 65, 67.
2018 Algorachelus parvus ; Pérez-García, p.
119, 132-134.
2020 Algorachelus parva ; Pérez-García, p.
366.
2020 Algorachelus parva ; Pérez-García, Bardet, Fregenal-Martínez, Martín-Jiménez, Mocho, Narváez, Torices, and Vullo, p.
2.
2024 Algorachelus parva ; Pérez-García and Rubio, p. 2-4.
Type material. The shell EY795 ( Figure 1 View FIGURE 1 A-B) corresponds to the holotype of ‘Podocnemis’ parva
(referred as HUJP-Testudinata-3 by Haas 1978a),
whose photographs, in dorsal and ventral views,
were published by Haas (1978a, figures 3 and 4,
respectively), as well as a schematic representation of the complete shell of the species, especially based on this individual (Haas, 1978a, figures 1
and 2). Three paratypes were established by Haas
(1978a): the partial carapace EY790 ( Figure 1F View FIGURE 1 ;
referred as HUJP-Testudinata-4 by Haas 1978a),
the partial skeleton EY797 ( Figures 2 View FIGURE 2 A-B, 3B-C;
referred as HUJP-Testudinata-2 by Haas 1978a),
and the shell EY792 ( Figure 2 View FIGURE 2 D-E; referred as
HUJP-Testudinata-1 by Haas 1978a). Photographs but no schematic representations of these paratypes were published (see figure 9 for EY790, figures 7-8 for EY797, and figures 5-6 for EY 792 in Haas, 1978a) .
Other referred specimens. Four additional specimens from the type locality and horizon are here recognized as attributable to Algorachelus parva . The shell EY791 ( Figure 1 View FIGURE 1 D-E) corresponds to the holotype of ‘ Podocnemis judaea’ (referred as HUJP 3664 by Haas 1978b), presented both through photographs (Haas, 1978b, figures 3 and 4) and schematic representations (Haas, 1978b, figures 1 and 2). The shell EY796 ( Figure 1C View FIGURE 1 ), the partial skeleton EY793 ( Figures 2C View FIGURE 2 , 3A View FIGURE 3 ), and the partial shell EY794 ( Figure 2F View FIGURE 2 ) correspond to so far unpublished specimens.
Type locality and horizon. ‘Ein Yabrud limestone quarry, near the village of Beit Eil, Binyamin Region, West Bank, Israel, Middle East. Bet-Meir Formation or the slightly younger Amminadava Formation, middle part of the Judea Group, lower or middle Cenomanian (see Khalloufi et al., 2010; Cawley and Kriwet, 2018; and references therein). Emended diagnosis. Member of Algorachelus differing from the other species of this genus by: a posterior carapace with evenly rounded, rather than nearly straight lateral sides; subtriangular to generally triangular first pair of marginals scutes, with short medial margins and a short overlap on the antero-lateral edges of the nuchal plate (covering less than half, and usually less than a third, of its length), and lacking a medial contact (i.e., allowing the first vertebral scute reaching the carapace margin) or showing a very short contact (i.e., the first vertebral occupying a position very close to that margin); wide vertebrals, the second being at least one and a half times wider than long; short anterior plastral lobe, not reaching the anterior carapace margin. It shares with Algorachelus peregrina , but not with Algorachelus tibert , the presence of a wider than long nuchal.
Description. All specimens referred here are represented by fully or partially articulated shells. The maximum carapace length reached approximately 22 cm in EY796 ( Figure 2C View FIGURE 2 ). The carapace morphology varies from subrounded ( Figures 1C View FIGURE 1 , 2D View FIGURE 2 ) to subelliptical ( Figure 2C View FIGURE 2 ). The posterolateral margins of the carapace ranged from gently curved ( Figures 1A View FIGURE 1 , 2A, C, D View FIGURE 2 ) to nearly straight ( Figure 1C, D View FIGURE 1 ). A slight ( Figures 1A, C View FIGURE 1 ; 2D View FIGURE 2 ) to almost absent ( Figure 2C View FIGURE 2 ) anterior notch, restricted to the nuchal plate and the medial half of the first pair of peripherals, is present on the anterior carapace margin.
The nuchal plate is wider than long ( Figures 1A, C, D View FIGURE 1 ; 2A, C, D View FIGURE 2 ). Its anterior margin is equal or greater than half of the maximum width of the plate. Although the most common condition is the presence of six neurals ( Figures 1A, C View FIGURE 1 ; 2A, C, D View FIGURE 2 ), seven may also be present (see specimen EY 791 in Figure 1D View FIGURE 1 ). The first neural is subrectangular ( Figures 1A, C, D View FIGURE 1 ; 2A, C, D View FIGURE 2 ), and the last one is pentagonal. The remainder are hexagonal and are generally longer than wide, with shorter antero-lateral than postero-lateral margins. Of the eight pairs of costals, a medial contact occurs between the sixth and the eighth in most specimens ( Figures 1A, C View FIGURE 1 ; 2A, C, D View FIGURE 2 ). However, contact occurs exclusively between the seventh and eighth pairs in EY791 ( Figure 1D View FIGURE 1 ). The suprapygal is subtriangular and approximately as wide as long ( Figures 1A, C View FIGURE 1 ; 2C View FIGURE 2 ) or slightly wider than long ( Figures 1D View FIGURE 1 , 2D View FIGURE 2 ). The pygal plate is approximately rectangular, and almost as wide as long.
The second vertebral scute is the widest and at least one and a half times wider than long ( Figures 1A, C, D View FIGURE 1 ; 2A, C View FIGURE 2 ). The first vertebral contacts the anterior carapace margin in EY795 ( Figure 1A View FIGURE 1 ) or reaches a position very close to it in others ( Figures 1C View FIGURE 1 ; 2A, C, D View FIGURE 2 ). Laterally, this scute contacts the second pair of peripherals ( Figure 1A, D View FIGURE 1 ) or a nearby position ( Figures 1C View FIGURE 1 , 2C View FIGURE 2 ). The contact between the first and second, second and third, third and fourth, and fourth and fifth vertebrals is located on the first, third, fifth or sixth, and last pair of costals, respectively ( Figures 1A, C, D View FIGURE 1 ; 2A, C, D View FIGURE 2 ). The pleural scutes overlap the medial region of the peripheral plates. The first pair of marginals is generally subtriangular, showing a short medial margin. The first marginal scutes are wider than long. The overlap of these scutes on the antero-lateral edges of the nuchal are short, equivalent to less than half ( Figure 2C View FIGURE 2 ) and even less than a third ( Figures 1D View FIGURE 1 ; 2D View FIGURE 2 ) of the length of the plate.
In ventral view, it is observed that the anterior plastral lobe is short, so that it does not reach the anterior edge of the carapace ( Figure 1B, E View FIGURE 1 ). The anterior plastral lobe is visibly shorter than the posterior lobe ( Figures 1B, E View FIGURE 1 ; 2B View FIGURE 2 ). The anterior lobe is broadly rounded but the lateral margins of the posterior are nearly straight. The entoplastral morphology varies from subhexagonal, being a third wider than long ( Figure 1B View FIGURE 1 ), to subrhomboidal, both dimensions being subequal ( Figures 1E View FIGURE 1 , 2B View FIGURE 2 ). A pair of subrounded and laterally positioned mesoplastra are present ( Figures 1B, E View FIGURE 1 ; 2B, E View FIGURE 2 ). There is a well-developed anal notch that is more than twice as wide as long, and its profile is V-shaped ( Figure 2B View FIGURE 2 ) or U-shaped ( Figures 1B, E View FIGURE 1 ; 2E View FIGURE 2 ).
The length of the gular scute is variable: in some specimens, it overlaps less than a quarter of the maximum entoplastral length (see specimen EY 791 in Figure 1E View FIGURE 1 ) but can reach the pectoral scutes in others (see specimen EY 795 in Figure 1A View FIGURE 1 ). When the latter condition is present, the humeral scutes lack a medial contact. The extragulars are triangular and show a relatively small size and can contact the anterior entoplastral margin (e.g., EY795; Figure 1B View FIGURE 1 ). The pectorals do not reach the epiplastra ( Figures 1B, E, F View FIGURE 1 ; 2B, F View FIGURE 2 ). However, they can overlap the anterior region of the mesoplastra (e.g., Figure 1B, E View FIGURE 1 ). A relatively long distance is observed between the anal scutes and the hypoplastra.
The skull is preserved in two individuals of Algorachelus parva studied herein (EY793 and EY797; Figures 2 View FIGURE 2 A-C; 3). They are exposed from the matrixin dorsal view ( Figure 3A, B View FIGURE 3 ). Both are dorsoventrally crushed. However, the skull is interpreted as a relatively wide element, its length being slightly greater than its width. It is wide along its entire length and has a short rostral region, with a well-defined anterior angle. The orbits are dorsolaterally facing. Nasals and an interorbital groove are absent. The prefrontals do not touch the parietals, due to the frontals contact along the midline ( Figure 3A, B View FIGURE 3 ). The prefrontals are longer than wide. The frontals are slightly wider than long. The parietals do not contact the orbits, but the jugals do. No interparietal or other cranial scutes are recognized. A relatively deep temporal emargination is present, partially covering the otic chamber. There is a well-developed supraoccipital crest, and the squamosals show a well-developed posterior projection.
The lower jaw is identified for EY797, and is only accessible in ventral view ( Figure 3C View FIGURE 3 ). It is robust. The sutures between the angular and the dentary are identified for both mandibular branches. The anterior angle defined by both branches is slightly obtuse, but the posterior angle between them is slightly acute.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.