【摘要】 描述了产自广西东部平乐下泥盆统贺县组的一脊椎动物群中的无颌类化石，建立了盔 甲鱼类的一新属、新种──平乐圆盘鱼（Ｄｉｓｃａｓｐｉｓ ｐｉｎｇｌｅｎｓｉｓ ｇｅｔ． ｅｔ ｓｐ． ｎｏｖ．）。圆盘鱼鳃囊 数目多达３２对。同层产出的尚有保存较完好的胴甲鱼目中华鱼科化石。该动物群的发现为 华南区早泥盆世晚期脊椎动物群的演化及其生物地层的对比提供了重要依据。更多还原

【Abstract】 The late Early Devonian vehebrate fossils including antiarehs and POlyb~hiaspids were collected from YUantou Valley, jingle County of Eastern Guangxi. The anhareh fOSsils were named Dayaoshania youngi by Wang Shitao in fotohie et al. (1992), and refermd tO the Sinolepidae. Dayaoshania has no median vental plate, similar tO Dujingolepis. Afchonolepis and Anolepis of SOuth China and Grenfellaspis of AuStlulia. In this Paper the polybaxhiaspid fossils are described, and the Discaspis pinglensiS- Dayaoshania youngi Paleoconuntalty is termed, represenhng the late Early Devonian PaleocOInmndty in the He-clan Formation of Guangxi (unnamed PaleoconUnwhty in Wang, 1991). Class Galeaspida SUbclass POlybranchiaspida Order DUyunolepidida Pan & Wang, 1978 FamnY DUyunolepidae Pan & wang, 1978 Genus ffecaspis gee. nov. diagnosis Chphalic shield covered by cycloid calapase with a round rostlal margin and without POsterior process; POsterior comers leaf--Shaped; nasO--hypophysial fenesthe slightly longitudinal round or cycloid; OrbitS round and ndddie size; hearty--tWopairs of branchial chambers and wide posterior cephalic region ladder shaped; Padem of sensory lines in the dorsal shield with tWo Phallel main lateral canals, one mediO--transversal co~sure and five latero--~versal canajs with the bifUI’Cated ends;a pair of curved sensory canajs siftting in the main lateral canals POstendarendly. Remarks TIs new form is similar in general shape tO polybaxhiaspidi Polybranchiaspis, DongfangaSPI’s and Dnyunolepis, particularly similar tO Dongfangaspis in the sensory lines and developed pectolal corners. It is different from POlybranchiaspis and DongfangaspiS from YUnnan in itS hearty--tWo branchial chambers. Discaspl’s differs from Duyunolepis in the number of b~hial chaxnbers, the curved sensory canals and the absence of the POsterior Process. Thaotongaspis janvieri (Wang and Zhu, 1994), tefened tO Polybranchiaspiformes and Zhaotongaspidae, heart thirty--five pairs of branchial chambers like the new genus, but differs in itS laterally plaaed orbitS. We refer those POlybranchiaspids with 20-35 airs of branchial chambers tO the DUyunaspidida. Type species DI’scaspis pinglensl’s sp. nov. (PI.I, l--3; PI.II, l--2; fig.2) Etymology The genus is from aden ixsca (cycloid), aspis (fish); the species is from the locality--jingle COunty. HOlotype GMV1952--l, 2, endocndum, dorsal view and itS extemaJ mould. Paratype GMV1953--l,2, cephalic shield, dorsal view, the baxhial region is well Preserved. oder mat6rial GMV1954, GMV1955--l, 2, GMV1956, the right senSOry lines and the median talsversal coedss~ are preserved very well in GMV1955--l and orwI955-2. Horizon and lOcality He-clan Formatioll, late Early Devonian (Emsian); YUantou Valley, angle COunty, Guangxi. Description The endoclanium, Particularly the branchial region is well preserved in the holotype GMV1952, and the large part of the dorsal caxapaCe is preserved in the Palatype GMV1953. The reconstrUChon of the sensory lines is based on the GMV1955 specimen since the right sensory lines and the mediO--tusversal coedssure are well preserved in the GMV1955. In GMV1956 the rosaal margin is slighUy convex anteriorly. There is no barn thee in any specimen. The measlesmentS of the specimens are shown in Table 1. Cephalic shield is covered by carapaCe with a round rosaal margin and without a posterior process. The POsterior comers are leaf--shaped. OrbitS are rOUnd and median--sized. There are hearty--tWo Pairs of hi’anchial chambers and wide posterior cephalic region in laddenshaped. A pair of curved sensory canals is sitUated in the main lateral canals POsteredatalally. MffitM (Explanations of plates) M$I abate I ) l --3. 4$N#t (#4. ##) (Discaspis pinglensis gee et sp. nov.) 1. E@#$(Holotype)GMV1952, --ffgM& M, WN$tthN$# (a complete cephalic shield showing branchial chambers of both sides) la. #M (in dorsal view), GMV1952--l, x 0.8; fo. &, ’F, (natura) cast of the cephalic shield), GMV1952--2, x 0.7; 2, &J@#$(Paratype), GMV1953, x 0.85, --SNM&M,W#T$#$t W, #W(a complete cephalic shield shoWillg Part of更多还原