【摘要】：鰓曳動(dòng)物是原口動(dòng)物亞界蛻皮類群中的一個(gè)小門,現(xiàn)生類型迄今只描述了7屬19種。然而,軟軀體鰓曳動(dòng)物卻是寒武紀(jì)海洋中底內(nèi)生物群落的優(yōu)勢(shì)類群,具有非常高的形態(tài)差異度和個(gè)體豐度。華南寒武紀(jì)臺(tái)地相和斜坡相一系列特異埋藏化石群保存有大量鰓曳動(dòng)物化石,是研究鰓曳動(dòng)物早期起源與輻射、蛻皮動(dòng)物起源與演化以及“寒武紀(jì)大爆發(fā)”等基礎(chǔ)前沿課題的重要化石材料。但是,目前學(xué)術(shù)界對(duì)早期鰓曳動(dòng)物的系統(tǒng)分類、輻射演化、古生態(tài)學(xué)特征和系統(tǒng)演化關(guān)系等問(wèn)題仍有較大爭(zhēng)議。在系統(tǒng)總結(jié)前人研究成果基礎(chǔ)上,本文對(duì)湖北三峽地區(qū)的石牌生物群(臺(tái)地相,寒武系第4階)、陜西西鄉(xiāng)三郎鋪地區(qū)的西鄉(xiāng)生物群(臺(tái)地相,寒武系第4階)、貴州劍河革東地區(qū)的劍河生物群(斜坡相,寒武系第4階晚期)和凱里生物群(斜坡相,寒武系第5階早期)等化石群中的鰓曳動(dòng)物化石材料進(jìn)行研究,力求對(duì)上述學(xué)術(shù)界長(zhǎng)期爭(zhēng)議的科學(xué)問(wèn)題有所解答。本文系統(tǒng)描述了四個(gè)生物群中的古蠕蟲(chóng)類化石5屬8種,包括3個(gè)新屬新種、2個(gè)新種和2個(gè)未定種。其中,Sanxiascolex papillogyrus gen. et sp. nov., Wronascolex yichangensis sp. nov.和W. spinosus (Ivanstsov and Wrona,2004)描述于石牌生物群；Shaanxiscolex xixiangensis gen. et sp. nov.為西鄉(xiāng)生物群的特有類型：Guizhouscolex balangensis gen. et sp. nov.和Yunnanscolex sp.是劍河生物群的兩個(gè)新類型；W. jianhensis sp. nov.和W.sp.則是凱里生物群的化石分子。此外,Gen. et sp. uncertain A和Gen. et sp. uncertain B是兩個(gè)分別描述于劍河生物群和凱里生物群的未正式命名新類型。這些化石屬種都具有常見(jiàn)于早古生代地層的Hadimopanella類骨板,但不同類型之間骨板系(scleritomes)特征均顯示出一定差異性,這與地史時(shí)期不同產(chǎn)地和層位古蠕蟲(chóng)類的骨板特征多不相同的情形相一致,說(shuō)明古蠕蟲(chóng)類的表皮骨板構(gòu)造可能與海底沉積物的性質(zhì)有關(guān)。論文系統(tǒng)討論了Wronascolex屬的分類原則、古地理分布和地史延限,結(jié)果表明該屬是寒武紀(jì)分異度最高(含8種和3未定種)、分布范圍最廣(華南、西伯利亞、澳大利亞、西班牙和北美)、延限時(shí)間最長(zhǎng)(寒武系第4階至鼓山階)的古蠕蟲(chóng)類實(shí)體化石。但是,Wronascolex的屬征仍不明確,而且Hadimopanella孤立骨板的形態(tài)分類研究爭(zhēng)議較大,大大削弱了該化石屬及其骨板的地層學(xué)意義。另外,石牌生物群中W. spinosus的骨板具有獨(dú)特的排列方式,表明古蠕蟲(chóng)類的骨板可能具有多種增長(zhǎng)模式。本文還研究了云南澄江動(dòng)物群中的古蠕蟲(chóng)類Mafangscolex yunnanensis (Luo et Zhang),1986,首次識(shí)別出該種軀干腹側(cè)有圓錐狀感覺(jué)構(gòu)造和可能的腿肢,為古蠕蟲(chóng)類形態(tài)學(xué)、古生態(tài)學(xué)和系統(tǒng)演化研究提供了新信息�；C據(jù)顯示,古蠕蟲(chóng)類具有較強(qiáng)的掘穴能力,部分類型可能兼有潛穴和底表爬行生活方式,并偶爾食含腐質(zhì)沉積物。盡管古蠕蟲(chóng)類部分孤立骨板類型(如Hadimopanella)的最早化石記錄可追溯到寒武系第二階晚期,但處于第三階的澄江動(dòng)物群代表鰓曳動(dòng)物的首次輻射演化事件。寒武紀(jì)時(shí)期不同化石群中鰓曳動(dòng)物的組合面貌差異很大,多數(shù)類型為各個(gè)生物群的特有分子,只有少數(shù)屬種具有較長(zhǎng)的地史延限,說(shuō)明早期鰓曳動(dòng)物在不同生活環(huán)境下有較好的適應(yīng)能力并發(fā)生快速分異演化。寒武紀(jì)早期揚(yáng)子臺(tái)地斜坡相至臺(tái)地相地層都有大量鰓曳動(dòng)物化石產(chǎn)出,表明華南滇東淺海地區(qū)未必是這一時(shí)期鰓曳動(dòng)物的輻射中心。凱里生物群產(chǎn)有重要鰓曳動(dòng)物類型Ottoia和Sicyophorus。研究結(jié)果顯示,凱里生物群的奧托蟲(chóng)體長(zhǎng)50-80 mm,外伸的翻吻有25列縱列吻刺,后部短柱形；軀干寬度較均勻,具密集環(huán)紋,達(dá)13條/5mm；咽部和腸道之間有一個(gè)可能的肌胃；腸道壁見(jiàn)肌纖維；軀干后部有1對(duì)長(zhǎng)的后伸縮肌。這些特征明顯不同于布爾吉斯頁(yè)巖生物群(Burgess Shale)中的O. prolifica Walcott,1911,命名為貴州奧托蟲(chóng)O. guizhouensis Yang, Zhao et Zhang,2015。原地埋藏的O. guizhouensis保存有蟲(chóng)體正在鉆泥掘穴的證據(jù),而且腸道有泥質(zhì)充填物,表明Ottoia是一種能在底表沉積物中多維度自由穿梭、偶爾食泥質(zhì)生活的底內(nèi)動(dòng)物,并非此前推測(cè)那樣穴居于U型管穴中。通過(guò)類比澄江動(dòng)物群中的特殊鰓曳動(dòng)物類型Sicyophorus rara Luo et al.,1999和Palaeopriapulites parvus Hou et al.,1999,識(shí)別出凱里生物群中葫蘆蟲(chóng)的軀干大約有50條縱列隔板,頸部有2-3條環(huán)紋,末端有一條較短的尾突構(gòu)造,因而建立貴州葫蘆蟲(chóng)(新種)S. guizhouensis sp. nov.。形態(tài)學(xué)和解剖學(xué)證據(jù)表明,Sicyophorus既有相似于鰓曳動(dòng)物的形態(tài)構(gòu)造(翻吻和尾突),也有類似于鎧甲動(dòng)物的軀干特征(具縱列隔板),而卷曲盤繞的腸道區(qū)別于其他環(huán)神經(jīng)類動(dòng)物,可能是鰓曳動(dòng)物向鎧甲動(dòng)物演化過(guò)程中幼態(tài)持續(xù)發(fā)育而來(lái)的一個(gè)特化類型。本文運(yùn)用TNT軟件對(duì)O. guizhouensis和S. guizhouensis的系統(tǒng)演化位置進(jìn)行分析。譜系分支樹(shù)顯示,Ottoia屬于Scalidophora干群類型,而Sicyophorus位于Scalidophora冠群底部靠近鎧甲動(dòng)物的位置,支持由鰓曳動(dòng)物幼態(tài)持續(xù)發(fā)育而來(lái)的觀點(diǎn)。此外,古蠕蟲(chóng)類不同屬種的系統(tǒng)演化位置差別很大。根據(jù)形態(tài)學(xué)、解剖學(xué)證據(jù)和譜系分析,論文討論了兩側(cè)對(duì)稱動(dòng)物祖先類型Urbilateria-葉足動(dòng)物Xenusia- Scalidophora干群類型Fieldiai和Ancalagonia—古蠕蟲(chóng)類Palaeoscolecida—Louisellia—鰓曳動(dòng)物Priapulida—葫蘆蟲(chóng)Sicyophourus—鎧甲動(dòng)物L(fēng)oricifera整個(gè)演化線系中各個(gè)節(jié)點(diǎn)動(dòng)物代表的身體構(gòu)型特征,認(rèn)為部分古蠕蟲(chóng)類(如M.yunnanensis)可能具有相似于蛻皮動(dòng)物祖先類型的形態(tài)特征。
[Abstract]:Branchial tracer is a small door in the subboundary molt group of the original animal, and the present type has only described 7 genera and 19 species so far. However, the soft somatic branchial tracer is the dominant group in the Cambrian middle subsea biological community, with very high morphological difference and individual abundance. A series of special burial of the Cambrian platform and slope facies in Southern China. The stone group has a large number of branchial fossils. It is an important fossil material for the study of the early origin and radiation of the branchial tracers, the origin and evolution of molt, and the "Cambrian outbreak". However, the systematic classification, radiological evolution, paleo ecological characteristics and systematic evolution of the early branchial tracers in the academic circles are at present. On the basis of a systematic summary of the achievements of previous studies, this paper is based on the stone brand biota in the Three Gorges area (terracostage, Cambrian fourth), Xixiang biota (terrace, Cambrian, fourth) in the Sanlun area, Xixiang, Xixiang, and the Jianhe biota (slope facies, late Cambrian in the late fourth order) and Kay in Jianhe, Guizhou. The study of the branchial fossil materials in the fossils of the fossils of the biota (slope facies and the Early Cambrian fifth order) has been studied in order to solve the scientific problem of the long term controversy in the academic circles. This paper systematically describes the 5 genera and 8 species of the paleo worms of the four biota, including 3 new species, 2 new species and 2 undetermined species. Among them, Sanxiasc Olex papillogyrus Gen. et sp. Nov., Wronascolex yichangensis sp. Nov. and W. spinosus, described in the Xixiang biota of biota. The two new types, W. jianhensis sp. Nov. and W.sp. are the fossil molecules of the Kaili biota. In addition, Gen. et sp. uncertain A and Gen. et are two unofficially named new types described respectively in the biota and the Kaili biota. These species are all common in the early Paleozoic strata. Bone plate, but the characteristics of different types of bone plate system (scleritomes) show a certain difference, which is consistent with the different characteristics of the bone plate characteristics of different habitats and layers of ancient worms in the period of geological history, indicating that the structure of the epidermal bone plate of the ancient worms may be related to the nature of the seabed sediments. This paper systematically discusses the Wronascolex genus. The classification principle, palaeogeographic distribution and earth history extension limit indicate that the genus is the highest (8 species and 3 undetermined species) in Cambrian (including 8 species and 3 undetermined species), and the most widely distributed (Southern China, Siberia, Australia, Spain and North America) and the oldest (Cambrian, fourth to GUSHAN) paleogeic solid fossils. However, the genera of Wronascolex are still not clear. Moreover, the study of the morphological classification of the Hadimopanella isolated bone plates has greatly weakened the Stratigraphic Significance of the fossil genus and its bone plate. In addition, the bone plate of the W. spinosus in the stone brand biota has a unique arrangement, indicating that the bone plates of the ancient worms may have a variety of growth patterns. This paper also studied the Chengjiang fauna of Yunnan. The ancient worms Mafangscolex yunnanensis (Luo et Zhang), 1986, identified the conical structure and possible leg limbs on the ventral side of the trunk for the first time. It provides new information for the study of the morphological, paleecology and systematic evolution of the ancient worms. Fossil evidence shows that the ancient worms have strong point digging ability and some types may have both potential and potential. Although the earliest fossil records of partial solitary bone plate types (such as Hadimopanella) can be traced back to the late Cambrian second stage of the Cambrian, the third order Chengjiang fauna represented the first radiative evolution of the branchial tract. The combination features of the tractable animals are very different. Most of them are endemic molecules of the various biota. Only a few species have a long history delay limit. It shows that the early branchial tracer had better adaptability and rapid differentiation in different living environments. The tracer fossils are produced, indicating that the Southern China East Yunnan shallow sea area is not necessarily the radiant center of the branchial tracts in this period. The Kaili biota produces an important branchial type Ottoia and Sicyophorus., which shows that the Otto body of the Kaili biota has a long 50-80 mm length, and the extended kiss has 25 columns of spines, a short column in the rear, and the trunk width of the trunk. Uniform, dense ring lines, up to 13 /5mm; there is a possible muscle stomach between the pharynx and the intestine; the intestinal wall appears muscle fiber; the trunk of the trunk has 1 pairs of long hind extention muscles. These characteristics are distinctly different from the O. prolifica Walcott in the Burgess Shale biota (Shale), 1911, named the O. guizhouensis Yang, Zhao of the Guizhou Otto worm, Zhao. Et Zhang, 2015. buried O. guizhouensis preserved the evidence that the body is drilling mud, and there is a muddy filling in the intestines, indicating that Ottoia is a kind of inward animal that can freely shuttle in the bottom surface sediments and occasionally live in mud. It was not previously assumed that the cavern was in the U cavern. By analogy with the Chengjiang fauna. The special branchial tracer types, Sicyophorus rara Luo et al., 1999 and Palaeopriapulites parvus Hou et al., 1999, identified the trunk of the cucurbits in the Kaili biota with about 50 column separators, 2-3 rings in the neck and a short tail process at the end, thus establishing the Guizhou cucurbits (new species) S. guizhouensis. Morphological and anatomical evidence shows that Sicyophorus has both morphological structure (kissing and caudate) similar to the branchial tracers, and also the trunk characteristics of the armour (with a column partition), while the curly coiled intestines are different from other annulus, and may be the continuous development of the branchlets during the evolution of the armour to the armour. This article uses TNT software to analyze the system evolution position of O. guizhouensis and S. guizhouensis. The branch tree of the pedigree shows that Ottoia belongs to the Scalidophora group type, and Sicyophorus is located at the bottom of the Scalidophora canopy near the position of the armour, supporting the continuous development of the branchial tractable immature state. In addition, the system evolution position of different species of ancient worms is very different. According to the morphological, anatomical evidence and genealogical analysis, the paper discusses the Xenusia- Scalidophora trunk type Fieldiai of the Urbilateria- leaf feet of bilaterally symmetrical animals and Ancalagonia - the Palaeoscolecida - Louisellia - branchial Priap Ulida - the body configuration characteristics of the representative of each node in the entire evolution line of the Sicyophourus - armour Loricifera of cucurbit cucurbit. It is believed that some of the ancient worms (such as M.yunnanensis) may have similar morphological characteristics to the ancestral types of the molting animals.
【學(xué)位授予單位】：西北大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類號(hào)】：Q915

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 ZHU Xuejian;PENG Shanchi;Samuel ZAMORA;Bertrand LEFEBVRE;CHEN Guiying;;Furongian(upper Cambrian) Guole Konservat-Lagersttte from South China[J];Acta Geologica Sinica(English Edition);2016年01期

2 劉玉娟;趙元龍;劉玉瑩;毛永琴;;貴州劍河八郎“清虛洞組”Kutorgina Billings,1861的初步研究[J];古生物學(xué)報(bào);2015年03期

3 羅惠麟;胡世學(xué);韓健;張世山;詹冬琴;盧玉喜;姚肖永;;云南晉寧梅樹(shù)村剖面古蠕蟲(chóng)再研究[J];西北大學(xué)學(xué)報(bào)(自然科學(xué)版);2014年06期

4 羅繡春;趙元龍;彭進(jìn);楊宇寧;潘永金;;貴州劍河八郎“清虛洞組”Protoryctocephalus Chow(Zhou) in Lu et al.,1974b的初步研究[J];古生物學(xué)報(bào);2014年03期

5 Han Zeng;Fangchen Zhao;Zongjun Yin;Guoxiang Li;Maoyan Zhu;;A Chengjiang-type fossil assemblage from the Hongjingshao Formation(Cambrian Stage 3) at Chenggong, Kunming, Yunnan[J];Chinese Science Bulletin;2014年25期

6 張興亮;舒德干;;寒武紀(jì)大爆發(fā)的因果關(guān)系[J];中國(guó)科學(xué):地球科學(xué);2014年06期

7 張培興;趙元龍;王平麗;楊宇寧;羅繡春;;貴州劍河八郎寒武系清虛洞組的楔葉形蟲(chóng)Sphenothallus Hall,1847[J];微體古生物學(xué)報(bào);2013年03期

8 段佰川;董熙平;;華南地區(qū)湖南省芙蓉統(tǒng)(上寒武統(tǒng))的古蠕蟲(chóng)骨片:個(gè)體生長(zhǎng)對(duì)表皮骨片形態(tài)的影響(英文)[J];北京大學(xué)學(xué)報(bào)(自然科學(xué)版);2013年04期

9 楊宇寧;趙元龍;彭進(jìn);楊興蓮;;貴州劍河八郎寒武系“清虛洞組”單板類化石Oelandiella[J];古生物學(xué)報(bào);2012年03期

10 傅曉平;伍孟銀;趙元龍;朱偉華;楊宇寧;;貴州劍河八郎寒武系都勻階“清虛洞組”宏觀藻類化石的發(fā)現(xiàn)[J];古生物學(xué)報(bào);2012年01期

相關(guān)會(huì)議論文 前1條

1 許俊文;;長(zhǎng)江三峽地區(qū)寒武系石牌組等深流沉積特征及其意義[A];中國(guó)地質(zhì)科學(xué)院宜昌地質(zhì)礦產(chǎn)研究所文集（19）[C];1994年

相關(guān)博士學(xué)位論文 前1條

1 韓健;澄江動(dòng)物群中翻吻動(dòng)物[D];西北大學(xué);2002年

，

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