A preliminary review of the fossil species of Ranina Lamarck, 1801 (Decapoda, Brachyura, Raninidae), with systematic remarks
Author
Pasini, Giovanni
Author
Garassino, Alessandro
text
Natural History Sciences
2017
2017-04-10
4
1
43
72
http://dx.doi.org/10.4081/nhs.2017.310
journal article
10.4081/nhs.2017.310
2385-0922
12753805
“
Ranina
”
burleighensis
Holland
in
Holland
& Cvancara, 1958
Fig. 20
Ranina
?
burleighensis
Holland
in
Holland
& Cvancara, 1958: 504
, 505, fig. 3c, Pl. 74, fig. 15.
Ranina burleighensis
-
Schweitzer
et al.
2010: 74
. –
De Angeli & Beschin 2011: 13
. –
Karasawa
et al.
2014: 260
.
Type material
:
holotype
,
USNM 562094
.
Type
locality
:
South of Moffit
,
Burleigh County
,
North Dakota
,
USA
.
Geological age
: Cannonball Formation, Paleocene.
Examined material
:
holotype
.
Description by
Holland
& Cvancara (1958)
: “
The
holotype
consists of the broken distal portion (twothirds?) of the left manus, the stub of the pollex or immovable finger, and the proximal part of the dactylus of a rather large propodus; the ma us, though laterally crushed, appears to have been oblong in cross-section with the width about three-fourths the height; the outer surface of the manus is covered with irregular spaced, asymmetrical tubercles which are inclined forward; between the tubercles are smaller, more symmetrical, rounded granules; inner surface similar but with the tubercles less pronounced; the tubercles apparently disappear toward the upper surface and on the pollex; on upper distal corners of the manus near the articulation of the dactylus is situated a pair of spine bases; the base of a single, small, forward-directed spine can still be seen on the outer surface near the junction with the pollex; the dactylus is so broken that it is impossible to determine its length; on the inferior surface a rounded projection appears near the break, 6.5 mm anterior to the junction with the manus; this projection is presumed to be the first prehensile tooth; at this place the dactylus is subovate but it expands rapidly in a proximal direction and becomes flatter on the superior surface; posteriorly directed projections occur on the upper proximal corners of the dactylus; the projections apparently articulated with poorly preserved sockets in the upper distal corners of the manus; a spine base of an anteriorly directed spine is borne on the distal edge of each projection (the inner spine was observed by the writer but broke during preparation); the dactylus is covered with irregularly spaced shallow pits; although little remains of the pollex, it appears almost rectangular in cross-section, pitted like the dactylus, and inclined downward from the manus.
”
Discussion
. Based upon the above-reported original description, this manus has strong propodus and dactylus that do not fit clearly the typical characters of a raninid manus. Indeed according to Feldmann (pers. comm., 2015) the manus clearly resembles that of a lobster or a xanthid. In conclusion, this species cannot be assigned to
Ranina
and this manus might well belong to a variety of other decapod groups.