禄丰古猿地点的小哺乳动物化石

过去十年,在禄丰古猿地点作了多次的发掘和筛洗,采集到包括食虫类,翼手类,啮齿类和兔形类在内的一千余件标本,使这一小哺乳动物的化石组合从1979年首次报道的6种增加到了38种,成为我国南方新第三纪中期最丰富而有代表性的小哺乳动物群。材料的初步鉴定表明:动物群中有代表我国首次发现的化石科和属;并有相当数量与华北、印巴次大陆和欧洲有密切亲缘关系的类型;其地质时代属最晚中新世保德期,相当于欧洲陆相哺乳动物分期的土洛里期(Turolian)。     

中国与欧洲晚中新世猪类比较研究:生物地层学及古生态学

猪类对比研究表明,从晚中新世初期到晚中新世末(或上新世初期),中国与欧洲的古气候、古环境和猪类演化都受到了全球性自然变化的影响,有着相同或相似的发展经历。晚中新世早期(early Vallesian(MN9))中国与欧洲的猪类显示它们均受到先前来自南亚猪类的影响,南亚猪类可能通过东南亚扩散到中国南方,通过西亚扩散到欧洲。晚中新世中期(lateVallesian(MN10)and early Turolian(MN11)),中国和欧洲的猪类与南亚已基本没有交流,在各自地区相对独立地演化发展。晚中新世晚期(late Turolian(MN12、MN13))中国北方除了保留有从南方迁移来的种类外,欧洲的猪类也已出现,此时中国(北方)动物群与欧洲动物群关系较为密切。南亚动物群在晚中新世早期(或者更早些)似乎已经和中国及欧洲的动物群分离。受青藏高原隆升等自然因素的影响,晚中新世中后期中国南方的古环境有一个从较为封闭、湿热的森林类型向相对开阔、干冷稀树草原类型的演变过程,而在此期间北方的自然环境则可能是从早期的半干旱疏林草原逐步发展到晚中新世末期的湿润林地。晚中新世欧洲自然环境有一个与中国南方相似的变化过程,比较而言,晚中新世中后期欧洲的环境可能比中国北方更为开阔和干冷。古气候和古环境变化是影响晚中新世猪类分布演化的决定性因素。     

甘肃董湾晚新近纪地层及中新统/上新统界线

古地磁测年表明,甘肃董湾晚新近纪剖面代表了7.3～3.5 Ma间的连续风成古土壤堆积。在74.8 m厚的剖面上,发现了小哺乳动物化石层位40个,共产出小哺乳动物39种。根据小哺乳动物组合特点,董湾剖面可以划分出4个生物地层带,Ⅰ+Ⅱ带为晚中新世晚期,相当于保德期;Ⅲ+Ⅳ带为上新世早期,相当于榆社期早期。中新统/上新统界线(5.33 Ma)位于剖面距顶部35.5 m处,比以鼢鼠Mesosiphneus最早出现为标志的生物地层Ⅲ带的底界低2 m。由于榆社阶底界直接对应于中新统/上新统界线,该剖面因其良好的地层和生物条件可被推荐为榆社阶界线层型的候选剖面。     

甘肃灵台文王沟(93002地点)晚中新世──早上新世生物地层

文王沟93002地点剖面从下至上被分成4个生物地层带。Ⅰ带可能属于晚中新世保德期中期,Ⅱ＋Ⅲ带属于上新世早期,Ⅳ带属于上新世中期。将各带与93001地点剖面进行了对比。着重探讨了鼠科动物中的Huaxiamys n. sp.向H.primitivus以及Occitanomys n. sp.向Chardinomys的演化规律。     

中国晚中新世陆相哺乳动物群序列:陕西蓝田的新证据(英文)

自 2 0世纪 60年代 ,陕西蓝田地区就以连续的晚新生代地层及丰富的哺乳动物化石而成为研究中国晚新生代哺乳动物与地层划分对比的经典地区之一。李传夔等 ( 1 984)根据灞河组发现的哺乳动物化石建立了灞河期 ,并与欧洲的Vallesian期对比。邱占祥等( 1 990 ,1 995)认为化石证据不充分 ,而将其与保德期合并。近年来 ,黄土高原三趾马红粘土大量的年代学资料表明 ,红粘土沉积最早可能开始于约 8Ma前。因此 ,狭义的保德期可能只代表了晚中新世晚期 ,晚中新世哺乳动物分期的再划分问题又重新被提出。自 1 997年以来 ,我们课题组在蓝田地区共发现 52个化石地点 ,其中的 2 6个含有哺乳动物化石 ,大哺乳动物化石标本共计 1 666件。经过详细野外地层测量 ,绘制了综合地层剖面 ,并将主要含哺乳动物化石的地点对比标定到综合地层剖面上。经过对各门类化石的初步研究 ,以及对已有化石材料的初步修订 ,到目前为止 ,陕西蓝田灞河组共计发现哺乳动物化石 45种 ,蓝田组 2 0种。新的化石证据表明 ,灞河组发现的哺乳动物化石组合完全不同于典型意义上的保德三趾马动物群。大哺乳动物化石以灞河三趾马与贾氏三趾马为代表 ,牛科化石组合在种级甚至属级上有明显的区别。大量的陕西转角羚羊 ,小型的Protoryx、Dorcadoryx以及Ga     

新疆准噶尔盆地北缘新近系顶山盐池组及相关地层问题

在新疆准噶尔盆地北缘乌伦古河流域建立了一个新近纪岩石地层单位:顶山盐池组。该组平行不整合于哈拉玛盖组之上,是一套以红色泥质粉砂岩为主体的细碎屑岩堆积,厚约50 m,含有上下两个化石带。上化石带时代为中新世晚期或上新世;下化石带为中中新世中晚期,与通古尔期默尔根小哺乳动物群大体相当。根据岩性和化石组合,推测顶山盐池组含有风成沉积物,或主要为风成堆积。其下部地层与流域中可可买登组为同期异相沉积。通过下伏的哈拉玛盖组,顶山盐池组可以和附近地区的铁尔斯哈巴合剖面衔接,构成乌伦古河流域一个从晚渐新世到中新世晚期或上新世大体连续的地层序列。这个序列有可能包含了塔本布鲁克期至保德期的沉积物和动物群。我们将这个序列与中国以及欧洲的相同时段生物年代序列进行了初步的对比,并讨论了有关的生物年代和年代地层问题。以哈拉玛盖动物群为代表的中中新世动物群的繁盛与它们的地理分布和中中新世全球气候最佳期的温暖气候可能相关。     

新疆其木干剖面中新世-上新世沉积物粘土矿物特征及其古气候指示意义

为重建新疆其木干地区中新世-上新世古气候,采用X射线衍射、扫描电子显微分析方法,对该区中新世-上新世沉积物中粘土矿物的相对含量、组合类型及显微形貌等进行了研究。结果显示:中新世早期-早中新世中期,沉积物中粘土矿物以伊利石和绿泥石为主,含少量的蒙脱石,表明以干旱气候为特征;晚中新世中期-早中新世晚期,伊利石的相对含量逐渐降低,且含有少量的蒙脱石和高岭石,指示相对温湿的气候条件;中新世晚期的粘土矿物组分与中新世早期相似,以伊利石和绿泥石为主,指示古气候以干旱为主导;晚中新世晚期至上新世伊利石相对含量降低,而蒙脱石和高岭石的相对含量升高,但由于粘土矿物中伊利石、绿泥石的含量仍然较高,指示古气候仍然以干旱为主导,但相对于中新世而言,这段时期为相对湿润期。以上结果表明,新疆其木干地区中新世-上新世古气候以干旱为主,并且气候经历了干旱-相对湿润-干旱-相对湿润的演化过程,但总体而言,本区中新世比上新世要更为干旱。     

禄丰古猿化石地点偶蹄目化石初步研究

云南,禄丰古猿化石地点经9次发掘,偶蹄目化石与哺乳类其他目一样,不仅材料增多,而且发现了新的属、种。经初步研究,由已记述的12种增加到22个种类,其中一部分是与华北时代相当于保德期的动物群有密切关系的属、种,另一部分是与南亚印、巴次大陆中西瓦立克动物群有亲缘关系的类型,其地质时代为中新世晚期,相当于欧洲陆相地层哺乳动物分期的土洛里。     

评欧亚晚新生代生物地层对比

随着人们对欧亚地区广泛分布的陆相沉积物研究的不断深入,不少地区性的陆相生物年代表(主要是哺乳动物生物年代表)相继问世(1853-1985).随之出现了许多进行洲内和洲际间生物年代对比的文章.新近的两篇文章(李、吴、邱,1984;薛祥煦,1984)建立并概述了中国晚新生代的陆相生物年代,并与欧洲地区作了对比.与此同时,本文作者发表了数篇讨论欧洲晚新生代哺乳动物生物年代及其对比的文章 (Kretzoi, 1983a, 1983b, 1984, 1985a, 1985b; Kretzoi-Pcsi, 1982).其中一篇讨论了欧洲与中国晚新生代生物年代对比的可能性 (Kretzoi, 1985b).许多殊途同归的观点是很令人满意的,但也有一些看法尚需探讨.这篇短文旨在促进双方观点的进一步交流.作者通过对比中国和欧洲晚新生代动物群进化阶段,认为下述问题尚需探讨或做更详尽的工作.1. 谢家期,作为一个时代的特征性的化石材料似太少,与欧洲进行生物年代对比尚有困难.2. 山旺期尽管有丰富的动物群为代表,但其中从早中新世至晚中新世的属种都有,恐怕不能直接与欧洲的奥尔良期 (Orlanian) 相比,需进一步作工作.3. 就目前所知,通古尔期在时间上较欧洲的阿斯塔拉期短,或仅相当于 Post-Astaracian = Monacian.4. 灞河期建期地点的哺乳动物并不是典型森林型的.相反,河南和山西等省的一些地点的哺乳动物的森林性质较欧洲的 Eppelsheim 期更明显.在中国,有希望将该期作进一步的划分.5. 保德期的材料是新第三纪所有动物群中最丰富的.无论从动物群或是分类单元的数量来说,都很有希望对东亚这一时间跨度作更详细的确定.并为解决新旧大陆之间最大的哺乳动物群的迁徙问题提供资料.6. 静乐期,这一时期是具特征性的.如果把一些含有真马的动物群从中排除,那么这个时期与西伯利亚—欧洲者是很不相同的.7. 游河期和更晚些的第四纪的"真马"动物群的时代的确定是令人满意的.这在整个欧亚大陆都是可以对比的,与北美的动物群的时代对比也是有希望的,而与热带地区动物群的比较仅在放射性绝对年龄的基础上才有可能.8. 新生代,尤其是晚新生代真兽类进化和动物群动力学主要受两个因素控制:中亚的辐射中心和白令海峡"气候筛".前者取决于古亚洲区的生境演化.中国古脊椎动物学的新成果将有效地推动人们去揭示这一广大地区上生命的进化过程,确信旧大陆陆地上生命历史的许多问题将通过中国同行们的工作得到澄清.     

中国新生代晚期的剑齿象(剑齿象科,长鼻目)及其扩散事件

对我国新生代晚期的剑齿象(Stegodon)进行再研究,提出了下列几点看法:1)依据Ste-godon的特征,可将已命名的中国剑齿象种分为3类。一类为有效的剑齿象种,包括晚中新世的S.licenti Teilhard & Trasseart,1937;上新世的S.zdanskyi Hopwood,1935和S.officinalis Hopwood,1935;上新世晚期至更新世早期的S.zhaotongensis Chow & Zhai,1962;更新世的S.chiai Chow & Zhai,1962,S.orientalis Owen,1870,S.sinensis Owen,1870和S.huananensis sp.n.等种。另一类是从剑齿象属中分出,归入到其他属或科的种。属于这一类的有可能置入真象类(Elephantoidae)的Stegodon parahypsilophus He,1984,S.guizhouensis Li & Wen,1986,Stegodon cf.S.hypsilophus和S.primitium Liu et al.,1973以及归入Stegolophodon的Ste-godon baoshanensis Yun,1975。第三类为属种分类位置未定的种,以S.wushanensis Huang et al.,1991为代表。2)南亚更新世的S.elephantoides(Clift),1828可能在我国不存在。3)我国的剑齿象化石相当丰富,发现于东经99°以东、北纬38°以南的广大地区(包括山西、陕西和甘肃以及华中、华南、西南和部分华东等地区),生存时代为晚中新世晚期至更新世。4)在新生代晚期我国的剑齿象可能经历了3次大的由北向南的扩散和迁移事件。第一次发生在晚中新世,第二次在晚中新世晚期至早上新世早期,第三次在更新世早期。5)剑齿象可能起源于亚洲。S.licenti是我国出现时代最早的剑齿象,也可能是剑齿象最原始的一种。     

东海陆架西南部台北坳陷新近纪孢粉植物群演替

对东海陆架西南部台北坳陷13口钻井孢粉分析表明,本地区新近纪植物群经历了3个发展阶段,即：1)早中新世早期松科花粉优势期;2)早、中中新世阿丁枫科花粉繁盛期;3)晚中新世至早上新世草本被子植物发展期。各时期孢粉植物群在横向上几乎没有大的区别,表明新近纪整个坳陷内构造与沉积环境及其变迁具有很好的一致性。植物群演替反映古气候从早中新世早期的湿润温凉到早、中中新世的暖湿,最后(晚中新世至早上新世)又趋温凉的变化历程。     

临夏盆地的新生代地层及其哺乳动物化石证据

临夏盆地的新生代地层相当发育 ,保存了从渐新世至全新世的连续沉积序列。更为重要的是 ,这些沉积物中含有丰富的哺乳动物化石 ,为划分和对比临夏盆地的新生代地层提供了可靠的证据。然而 ,此前关于这个盆地地层层序和时代的认识有许多矛盾之处 ,地层命名繁复 ,化石证据混乱。近年来我们对临夏盆地的野外考察已理清了沉积序列 ,并在充分的哺乳动物化石证据的基础上重新厘定了各个岩石地层单位所对应的地质时代。临夏盆地的新生代哺乳动物化石以晚渐新世的巨犀动物群、中中新世的铲齿象动物群、晚中新世的三趾马动物群和早更新世的真马动物群最为丰富。     

Evolution of bird communities in the Neogene of Central Asia,with a review of the Neogene fossil record of Asian birds

A complete taxonomic review of Neogene birds of continental Asia is provided. To date, avifauna from the latter half of the Miocene and Pliocene of Central Asia (Mongolia and adjacent regions of Inner Asia) are most thoroughly investigated. Available data enable a reconstruction of successive replacement of Early and Middle Miocene avifaunas by communities of the Recent type. Middle Miocene avifaunas of Mongolia include a great number of extinct genera and species, many of which were widespread in Eurasia. Extant genera became dominant in the Late Miocene and taxa close to living species appear in the Late Pliocene fossil record. Late Pliocene communities of birds of Central Asia were complex in genesis, composed of Miocene relicts (Struthio), immigrants from the European regions of the Palearctic (phasianid Plioperdix), North American immigrants (Calcarius), and also autochthonous elements, the origin of which is apparently connected with the arid belt of Central Asia (diverse passerines).     

Middle Eocene–Early Pliocene Subantarctic planktic foraminiferal biostratigraphy of Site 1090, Agulhas Ridge

The analysis of planktic foraminiferal assemblages from Site 1090 (ODP Leg 177), located in the central part of the Subantarctic Zone south of South Africa, provided a geochronology of a 330-m-thick sequence spanning the Middle Eocene to Early Pliocene. A sequence of discrete bioevents enables the calibration of the Antarctic Paleogene (AP) Zonation with lower latitude biozonal schemes for the Middle–Late Eocene interval. In spite of the poor recovery of planktic foraminiferal assemblages, a correlation with the lower latitude standard planktic foraminiferal zonations has been attempted for the whole surveyed interval. Identified bioevents have been tentatively calibrated to the geomagnetic polarity time scale following the biochronology of Berggren et al. (1995). Besides planktic foraminiferal bioevents, the disappearance of the benthic foraminifera Nuttallides truempyi has been used to approximate the Middle/Late Eocene boundary. A hiatus of at least 11.7 Myr occurs between 78 and 71 m composite depth extending from the Early Miocene to the latest Miocene–Early Pliocene. Middle Eocene assemblages exhibit a temperate affinity, while the loss of several planktic foraminiferal species by late Middle to early Late Eocene time reflects cooling. During the Late Eocene–Oligocene intense dissolution caused impoverishment of planktic foraminiferal assemblages possibly following the emplacement of cold, corrosive bottom waters. Two warming peaks are, however, observed: the late Middle Eocene is marked by the invasion of the warmer water Acarinina spinuloinflata and Hantkenina alabamensis at 40.5 Ma, while the middle Late Eocene experienced the immigration of some globigerinathekids including Globigerinatheka luterbacheri and Globigerinatheka cf. semiinvoluta at 34.3 Ma. A more continuous record is observed for the Early Miocene and the Late Miocene–Early Pliocene where planktic foraminiferal assemblages show a distinct affinity with southern mid- to high-latitude faunas.     

New observations on the Late Miocene–Early Pliocene Lutrinae (Mustelidae: Carnivora,Mammalia) from the Middle Awash,Afar Rift,Ethiopia

New observations on the Late Miocene and Earliest Pliocene mustelids from the Middle Awash of Ethiopia are presented. The Middle Awash study area samples the last six million years of African vertebrate evolutionary history. Its Latest Miocene (Asa Koma Member of the Adu-Asa Formation, 5.54–5.77 Ma) and Earliest Pliocene (Kuseralee and Gawto Members of the Sagantole Formation, 5.2 and 4.85 Ma, respectively) deposits sample a number of large and small carnivore taxa among which mustelids are numerically abundant. Among the known Late Miocene and Early Pliocene mustelid genera, the Middle Awash Late Miocene documents the earliest Mellivora in eastern Africa and its likely first appearance in Africa, a new species of Plesiogulo, and a species of Vishnuonyx. The latter possibly represents the last appearance of this genus in Africa. Torolutra ougandensis is known from both the Late Miocene and Early Pliocene deposits of the Middle Awash. The genus Sivaonyx is represented by at least two species: S. ekecaman and S. aff. S. soriae. Most of the lutrine genera documented in the Middle Awash Late Miocene/Early Pliocene are also documented in contemporaneous sites of eastern Africa. The new observations presented here show that mustelids were more diverse in the Middle Awash Late Miocene and Early Pliocene than previously documented.     

Diatom biostratigraphy of Late Miocene and Pliocene sediments of eastern Java (Indonesia)

A study of the marine diatoms of the Late Miocene to Pliocene Njepung section (Java) yield results that are in substantial agreement with Saint-Marc and Suminta (1979). The lower part of the Globigerina Marls belongs to the Late Miocene/Early Pliocene Thalassiosira convexa zone of Burckle (1972) while the middle of the formation belongs to the Middle Miocene Nitzschia jousea zone of Burckle (1972). An open ocean environment is indicated while the abundant presence of Thalassiosira nitzschioides suggests strong upwelling, at least in the lower part of the Globigerina Marls.     

Neogene lake systems of Central and South-Eastern Europe: Faunal diversity, gradients and interrelations

The gastropod γ-diversity of 12 Neogene lake systems is evaluated. In total, 1184 gastropod taxa from 119 localities are recorded deriving from the Early Miocene Rzehakia Lake System, the Early to Middle Miocene Dinarid Lake System, Lake Skopje, the Paratethyan Sarmatian lakes and the South German lakes, the Late Miocene Lake Pannon, the Pliocene lakes Dacia, Transylvania, Slavonia, Kosovo and Šoštanj as well as the Holocene Lake Petea. Each lake system is characterised according to its faunistic inventory and endemism. According to their gastropod faunas the lakes may be divided into pyrgulid-, hydrobiid-, viviparid- and planorbid-dominated ones. The generally high endemism rate is between 60 and 98%. Species diversity and generic diversity are strongly correlated. In contrast, neither endemism nor lake size are tightly linked with γ-diversity. Outstandingly high diversities such as observed for Lake Pannon are rather a result of the combined effect of autochthonous evolution in a long-lived system and accumulation of inherited elements. Examples of parallel evolution in lymnaeids and planorbids are presented.     

A temporally dynamic approach for cladistic biogeography and the processes underlying the biogeographic patterns of North American deserts

We implemented a temporally dynamic approach to the cladistic biogeographic analysis of 13 areas of North American deserts and several plant and animal taxa. We undertook a parsimony analysis of paralogy‐free subtrees based on 43 phylogenetic hypotheses of arthropod, vertebrate and plant taxa, assigning their nodes to three different time slices based on their estimated minimum ages: Early‐Mid‐Miocene (23?7 Ma), Late Miocene/Pliocene (6.9?2.5 Ma) and Pleistocene (2.4?0.011 Ma). The analyses resulted in three general area cladograms, one for each time slice, showing different area relationships. They allowed us to detect influences of different geological and palaeoclimatological events of the Early‐Mid‐Miocene, Late Miocene/Pliocene and Pleistocene that might have affected the diversification of the desert biota. Several diversification events in the deserts of North America might have been driven by Neogene uplift, marine incursion and the opening of the California Gulf during the Miocene–Pliocene, whereas climatic fluctuations had the highest impact during the Pleistocene.     

Neogene planktonic foraminiferal biostratigraphy and evolution: Equatorial to subantarctic, South Pacific

Detailed planktonic foraminiferal zonations have been established for the Neogene (Latest Oligocene through present) in six DSDP sites in the South Pacific ranging from equatorial to subantarctic latitudes (48°S). Two basic zonal schemes are readily recognized: tropical and temperate. The tropical zonation is best developed in DSDP Site 289 and the temperate zonation in Sites 206, 207A and 284. Tropical and temperate zonations can be linked by a warm subtropical scheme in Site 208, because this sequence includes a mixture of tropical and temperate elements. A site located close to the Subantarctic Convergence (Site 281) contains a zonation largely of temperate character, but the present of cooler elements and some differences in biostratigraphic ranges have required a slightly different biostratigraphic scheme.Although two broad schemes are recognized, none of the biostratigraphic sequences are identical between any of the sites. This reflects differences in biogeography, evolution and diachronous extinction at various latitudes during the entire Neogene. Diachronism in biostratigraphic ranges continue to create difficulties in correlation across such wide latitudes.Our detailed work has required the establishment of new biostratigraphic zonations in certain parts of the Neogene sequence and modifications in some other parts. Otherwise, previously established schemes are followed as closely as possible. In the temperate region, a new zonation has been established for the Early Miocene to early Middle Miocene. For the remainder of the Neogene the zonation of Kennett (1973) has been largely used. The tropical zonation of Blow (1969) is employed in the equatorial Site 289, but with further subdivisions for Zones N4 and N17. For areas intermediate between tropical and temperate latitudes (Site 208), a modified Early Miocene zonation is established based on changes in tropical and temperate elements.The zonal schemes are established on taxa that exhibit both diachronous and isochronous ranges across the latitudes. Zones that are at least partly diachronous include the Globigerinoides trilobus and Globorotalia miozea Zones of Early Miocene age; perhaps the Globorotalia mayeri Zone (its base) of the Middle Miocene; the Globorotalia conomiozea Zone of the Late Miocene; and the Globorotalia crassaformis Zone of the Early Pliocene.A large number of datum levels are recognized based on first evolutionary appearances or extinctions. The most widely applicable datums are as follows: latest Oligocene — Globigerinoides F.A.; Early Miocene — Globoquadrina dehiscens, F.A., Globorotalia kugleri L.A., Catapsydrax dissimilis L.A. and Praeorbulina glomerosa F.A.; Middle Miocene — Orbulina suturalis F.A., Globorotalia peripheroacuta F.A., Fohsella lineage L.A., Globorotalia mayeri L.A.; Late Miocene — “Neogloboquadrina” continuosa L.A., Globoquadrina dehiscens L.A., Globorotalia cibaoensis F.A.; Early Pliocene — Globorotalia puncticulata F.A., Globorotalia margaritae F.A.; Early Pleistocene — Globorotalia truncatulinoides F.A. A number of other datums are identified which assist with correlation over more restricted latitudinal ranges.The evolution of most Neogene planktonic foraminifera is now well established for a wide range of water masses. Evolutionary lineages are primarily centered in the temperate and tropical regions. Tropical lineages have recently been reviewed by Srinivasan and Kennett (1981) and are not discussed in detail here. However, Sphaeroidinellopsis seminulina is now considered to have evolved directly into S. paenedehiscens during the Late Miocene and S. subdehiscens Blow is considered to be junior synonym of S. seminulina.A new evolutionary lineage is recognized in the warm subtropics (Site 208) whereby Globigerina woodi woodi gave rise to Globigerinoides subquadratus via Globigerina brazieri. The discovery of this lineage clearly demonstrates that Globigerinoides is a polyphyletic “genus”. Another major phylogenetic lineage is recognized within the temperate globorotaliids of Early Miocene age as follows: “N.” continuosa → Globorotalia zealandica incognita → G. zealandica zelandica → G. praescitula → G. miozea. Although parts of this lineage have been recognized earlier, the entire phylogeny has previously been underscribed.A new Early to Middle Miocene lineage is recognized in the subantarctic to temperate areas which involve a transition from Globorotalia praescitula to G. challengeri n. sp. via intermediate forms.Two major Neogene globorotaliid lineages — the Menardella of the tropics and Middle Miocene to Recent forms of Globoconella of the temperate areas — are both considered to have evolved from Globorotalia praescitula beginning in the Early Miocene. This evolution initially was restricted to temperate areas but has since separated into distinctly tropical and temperate phylogenetic elements.     

Genetic divergence in Greek populations of the genus Leuciscus and its evolutionary and biogeographical implications

In 23 populations of Greek Leuciscus ( Squalius ), the percentage of polymorphic allozyme loci ranged between 0·034 and 0·379 (P=0·19) and expected heterozygosity was 0·011–0·166 (H_e=0·067). Current taxonomy is confusing and does not correspond to genetic data that support the presence in Greece of at least seven different species: L. cephalus , L. peloponnensis , L. prespensis , L. moreoticus , L. borysthenicus , L. keadicus and Leuciscus sp. from Euboea Island. The maximum Nei modified genetic distance was found among L. keadicus and the rest of subgenus Squalius populations D * Nei=0·446–0·705). Accepting the molecular clock hypothesis, speciation for the genus Leuciscus in Greece must have occurred during the Cenozoic period (between the Middle Miocene and the Later Pliocene). The two main biogeographical events causing speciation on mainland Greece were the Uplift of the Pindic cordillera and the isolation of the southern part of Peloponnesus. The faunistic composition of the lakes studied, in which new taxa are reconsidered, suggests the same faunistic origin in the Early Pliocene for Lakes Prespa and Stymphalia and a younger one in the Late Pliocene for Lake Trichonis. Euboea Island was not a zoogeographical unit during the Cenozoic. The isolation of all the freshwater fish fauna of Euboea has occurred since the Pliocene. The biogeographical model proposed here differs from classical hypotheses in considering of lesser importance the dispersion of L. cephalus on the Greek mainland during the Neogene and Quaternary.