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Journal of Paleontology 91(1):100–115
Etymology.—The trivial name refers to the relatively large size of specimens referred to this species.
Types.—Holotype, LPI-40749, and paratypes LPI-41683, 41684, 41648, 41689, 33341, and 41390.
Remarks.—Specimens referred to Yunnanocopia grandis are preserved in both dorsal and ventral aspect. The anterior appendages and the cephalic region tend to be well represented, and the thoracic region is poorly exposed or absent axially, but well represented laterally. Pre-cervical and cervical grooves are well impressed, and the pleon and tail elements are well pre- served. Several specimens exhibit parts of the endophragmal skeleton that bears a close resemblance to that seen in Schimperella acanthocercus, consisting of biconcave forward rays emanating from the midline. However, the rays are some- what thicker on S. acanthocercus. Pleonal sternites on both species form triangular extensions from the axial region; the anterior and posterior rays of those of S. acanthocercus project axially at the same angle, whereas those of Y. grandis do not. The anterior ray lies in a nearly transverse position, and the posterior ray is directed posteriorly. Ventral views of the ster- nites of S. acanthocercus are not in evidence because those specimens tend to be preserved in dorsal or lateral aspect.
Yunnanocopia longicauda new species Figures 5.1–5.6, 6.1–6.6, 7.1–7.6, 9
Diagnosis.—Long, slender eucopiids. Third article of anten- nular base longer than second; antennal scales lanceolate, sharp tipped; rostrum long, slender; endophragm narrow, apparently straight sided; pleonal tergites appear to be smooth; pleura strongly reduced; telson much longer than wide, margins con- vex, narrowing slightly posteriorly; uropods very long, slender.
Description.—Antennular base with first segment longer than wide, rectangular, about two-thirds as wide as antennal scale; second article rectangular, wider than long; third article tapering
distally, wider than long, longer than second article; antennular flagella stout. Antennal scales lanceolate, sharp tipped, thick- ened on smooth outer margin. Antennal flagellum(?) lies ventrally below antennal scale. In lateral view dorsal surface of antennal scale is arcuate, much longer than wide. There may be a diaeresis on the antennal scale. Specimen 41569 shows breaks on both sides that could be where diaeresis is positioned. Other specimens show what might be breaks, but 41770 does not show the diaeresis, so its presence is equivocal. Rostrum(?) long. Precervical grooves extend anteroven-
trally and then curve posteroventrally. Cervical groove a concave-forward arc all the way across the carapace. Eyes on very short stalks, large; stalks about 0.33mm long. Six or seven thoracomeres visible in ventral view. Six or seven apodemes visible. Apodemes are straight axially, then angle poster- olaterally laterally. Six, maybe seven, coxal holes on left side. Entire endophragm narrow, apparently straight sided. Coxal bases closely spaced, making entire endophragm
quite narrow. At least six thoracic appendages poorly preserved, segmentation not visible, terminations not visible.
Pleonal somites rectangular; 1 through 3 about same
length, 4 and 5 about equal in length; sixth pleonite longer than others. Pleonite 4 narrower than others. Intestinal tract well preserved, narrow, packed with globular pellets posteriorly; pleonal somites well preserved; terga appear to be smooth; pleura strongly reduced, rounded rectangular, weakly rimmed, arcuate groove or rim anteriorly on somites, convex forward, directed posteroventrally in lateral view. Pleopods on somites 3, 4, and 5 appear to have long, narrow elements proximally. Telson much longer than wide, margins weakly convex,
narrowing slightly posteriorly, widest about one-third distance posteriorly. Telson short compared to uropods. Uropods very long, slender, outer margin entire, with straight diaeresis. Uropodal exopod anterior and posterior to diaeresis long- itudinally striate for entire length. Rectangular (cylindrical) objects surrounding the specimen
may be fecal pellets.
Etymology.—The trivial name alludes to the extremely long, slender uropods.
Types.—Holotype LPI-41569, and paratypes LPI-41686, 41571, 41770, 41573, 32333, 41694, 32549, and 41696.
Remarks.—Three characters aligned these specimens to Eucopiidae: an antennal scale with a smooth outer margin, normal-sized eyes, and uropods with a smooth outer surface. Beyond those characters, Yunnanocopia longicauda also bears some resemblance to its congener, Y. grandis, so that placement in the same genus is warranted. The two species share a lanceolate to ovate antennal scale with acute tip, an antennular base with the first segment larger than the others, a precervical groove that does not cross the midline, a concave-forward cervical groove, strongly reduced to absent pleonal pleura, and no indication of setae on the tail fan. The relative size of elements two and three in the
antennular base is different in the two species in that the third element is small and triangular in Y. grandis (Fig. 8.2), whereas that in Y. longicauda (Fig. 8.3) is approximately the same size as the second element and has a more rounded terminus. The antennal scale on Y. longicauda is broader and has a thickened outer margin, whereas the antennal scale is narrower and not obviously thickened on the margin of Y. grandis. The endophragm of Y. grandis is weakly convex laterally, whereas that of Y. longicauda is straight sided, corresponding to the overall shape of the organisms in that Y. grandis is more stout than the slender Y. longicauda. Ornamentation of nodes on the terga of Y. grandis contrasts with the smooth tergal surface of Y. longicauda. Reduced pleura are present on Y. longicauda, but are not evident on Y. grandis. Pleonite 6 is shorter on Y. grandis than on Y. longicauda, although that structure is longer than the other pleonites in each species (Fig. 8.2, 8.3). The telson of Y. grandis is long and spatulate and that of Y. longicauda is shorter and more rounded at the tip. The length of the uropods of the former is shorter than that of the latter. Clearly, the two forms are distinctly different morphologi-
cally. In addition, Y. grandis is less numerous and occurs as isolated individuals in the Luoping assemblage, whereas Y. longicauda is more numerous and occurs as swarms
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