Middle Miocene Climatic Optimum

Continental scale studies on ungulate crown heights in relation to climate and habitat changes have revealed a correlation between increasing hypsodonty and a shift to more arid environments. Small mammals have been shown to adapt to changing habitats millions of years earlier than larger mammals. In this study I examined fossil localities throughout the last 37 Ma across North America. Diversity of rodents and lagomorphs were analyzed through this time period, with examination of community structure characterized by relative percentages of taxa with different crown heights. Overall, a decrease in precipitation and temperature was found across North America from 37 Ma to the present. The Mid Miocene Climatic Optimum (around 15 Ma) was an pronounced period of warming, comparable to the warming we see today. Nebraska and California showed increases in crown height before Oregon. Overall, these findings help demonstrate how communities react at different time scales to climate change. Fossil Sites .

Specimen records are a major source of species information for biodiversity research. However, specimen records currently available may be geographically or environmentally biased. Detailed knowledge of biases is useful for understanding and accounting for errors they introduce into analyses of biodiversity patterns. Here we study geographical and environmental biases in online records representing the flora of the Colombian Andes and explore their effect on sample completeness at different spatial scales. We found a strong geographical and environmental sampling bias. Plant records were concentrated close to cities where herbaria and researchers are located. The highlands > 2000 m are better sampled, whereas mid- and lowlands remain poorly sampled (i.e. montane and lowland forest). Sampling completeness (SC) median across the Colombian Andes is < 75% at the scales studied. We explore possible causes of sampling bias, identify critical gaps and priority areas for plant samplin...

The middle Miocene climate transition (MMCT) was a phase of global cooling possibly linked to decreasing levels of atmospheric CO 2. The MMCT coincided with the European Mammal Faunal Zone MN6. From this time, important biogeographic links between Anatolia and eastern Africa include the hominid Kenyapithecus. Vertebrate fossils suggested mixed open and forested landscapes under (sub)tropical seasonal climates for Anatolia. Here, we infer the palaeoclimate during the MMCT and the succeeding cooling phase for a middle Miocene (14.8-13.2 Ma) intramontane basin in southwestern Anatolia using three palaeobotanical proxies: (i) Köppen signatures based on the nearest living-relative principle; (ii) leaf physiognomy analysed with the Climate Leaf Analysis Multivariate Program (CLAMP); (iii) genus-level biogeographic affinities of fossil flora with modern regions. The three proxies reject tropical and hot subtropical climates for the MMCT of southwestern Anatolia and instead infer mild warm temperate C climates. Köppen signatures reject summer-dry Cs climates but cannot discriminate between fully humid Cf and winter-dry Cw; CLAMP reconstructs Cf climate based on the low X3.wet/X3.dry ratio. Additionally, we assess whether the palaeobotanical record resolves transitions from the warm Miocene Climatic Optimum (MCO, 16.8-14.7 Ma) to the MMCT (14.7-13.9 Ma), and a more pronounced cooling at 13.9-13.8 Ma, as reconstructed from benthic stable isotope data. For southwestern Anatolia, we find that arboreal taxa predominate in MCO flora (MN5), whereas in MMCT flora (MN6) abundances of arboreal and non-arboreal elements strongly fluctuate, indicating higher structural complexity of the vegetation. Our data show a distinct pollen zone between MN6 and MN7 + 8 dominated by herbaceous taxa. The boundary between MN6 and MN7 + 8, roughly corresponding to a first abrupt cooling at 13.9-13.8 Ma, might be associated with this herb-rich pollen zone.

The middle Miocene climate transition (MMCT) was a phase of global cooling possibly linked to decreasing levels of atmospheric CO 2. The MMCT coincided with the European Mammal Faunal Zone MN6. From this time, important biogeographic links between Anatolia and eastern Africa include the hominid Kenyapithecus. Vertebrate fossils suggested mixed open and forested landscapes under (sub)tropical seasonal climates for Anatolia. Here, we infer the palaeoclimate during the MMCT and the succeeding cooling phase for a middle Miocene (14.8-13.2 Ma) intramontane basin in southwestern Anatolia using three palaeobotanical proxies: (i) Köppen signatures based on the nearest living-relative principle; (ii) leaf physiognomy analysed with the Climate Leaf Analysis Multivariate Program (CLAMP); (iii) genus-level biogeographic affinities of fossil flora with modern regions. The three proxies reject tropical and hot subtropical climates for the MMCT of southwestern Anatolia and instead infer mild warm temperate C climates. Köppen signatures reject summer-dry Cs climates but cannot discriminate between fully humid Cf and winter-dry Cw; CLAMP reconstructs Cf climate based on the low X3.wet/X3.dry ratio. Additionally, we assess whether the palaeobotanical record resolves transitions from the warm Miocene Climatic Optimum (MCO, 16.8-14.7 Ma) to the MMCT (14.7-13.9 Ma), and a more pronounced cooling at 13.9-13.8 Ma, as reconstructed from benthic stable isotope data. For southwestern Anatolia, we find that arboreal taxa predominate in MCO flora (MN5), whereas in MMCT flora (MN6) abundances of arboreal and non-arboreal elements strongly fluctuate, indicating higher structural complexity of the vegetation. Our data show a distinct pollen zone between MN6 and MN7 + 8 dominated by herbaceous taxa. The boundary between MN6 and MN7 + 8, roughly corresponding to a first abrupt cooling at 13.9-13.8 Ma, might be associated with this herb-rich pollen zone.

The middle Miocene climate transition (MMCT) was a phase of global cooling possibly linked to decreasing levels of atmospheric CO 2. The MMCT coincided with the European Mammal Faunal Zone MN6. From this time, important biogeographic links between Anatolia and eastern Africa include the hominid Kenyapithecus. Vertebrate fossils suggested mixed open and forested landscapes under (sub)tropical seasonal climates for Anatolia. Here, we infer the palaeoclimate during the MMCT and the succeeding cooling phase for a middle Miocene (14.8-13.2 Ma) intramontane basin in southwestern Anatolia using three palaeobotanical proxies: (i) Köppen signatures based on the nearest living-relative principle; (ii) leaf physiognomy analysed with the Climate Leaf Analysis Multivariate Program (CLAMP); (iii) genus-level biogeographic affinities of fossil flora with modern regions. The three proxies reject tropical and hot subtropical climates for the MMCT of southwestern Anatolia and instead infer mild warm temperate C climates. Köppen signatures reject summer-dry Cs climates but cannot discriminate between fully humid Cf and winter-dry Cw; CLAMP reconstructs Cf climate based on the low X3.wet/X3.dry ratio. Additionally, we assess whether the palaeobotanical record resolves transitions from the warm Miocene Climatic Optimum (MCO, 16.8-14.7 Ma) to the MMCT (14.7-13.9 Ma), and a more pronounced cooling at 13.9-13.8 Ma, as reconstructed from benthic stable isotope data. For southwestern Anatolia, we find that arboreal taxa predominate in MCO flora (MN5), whereas in MMCT flora (MN6) abundances of arboreal and non-arboreal elements strongly fluctuate, indicating higher structural complexity of the vegetation. Our data show a distinct pollen zone between MN6 and MN7 + 8 dominated by herbaceous taxa. The boundary between MN6 and MN7 + 8, roughly corresponding to a first abrupt cooling at 13.9-13.8 Ma, might be associated with this herb-rich pollen zone.

6. T h e S te b n y k F o rm a tio n (M io c e n e) in th e B o ry s la v-P o k u tty a an d S a m b ir n a p p e s o f th e U k ra in ia n C a rp a th ia n s : a re c o rd o f e n v iro n m e n ta l ch a n g e in th e C a rp a th ia n F o re d e e p. G e o lo g ic a l Q u a rte rly , 60 (2): 4 7 3-4 9 2 , d o i: 10 .7 3 0 6 /g q .1 290 Th e late E a rly-M id d le M io c e n e S te b n y k F o rm a tio n is a-6 0 0-2 0 0 0 m th ic k u n it o f th e B o ry s la v-P o k u tty a a n d S a m b ir n a p p e s, w h ic h c o n ta in s a m o la s s e s u c c e s s io n o f th e C a rp a th ia n F o re d e e p in c o rp o ra te d w ith in th e m a rg in a l p a rt o f th e O u te r E a ste rn C a rp a th ia n a c c re tio n a ry w e d g e. In th e v a lle y o f th e P ru t R iver, b e tw e e n D e lia tyn a n d L a n ch yn , th e S te b n y k F o rm a tio n o v e r lie s th e a llu v ia l fan d e p o s its o f th e S lo b o d a C o n g lo m e ra te a n d th e d e lta ic d e p o s its o f th e D o b ro tiv F o rm a tio n in th e so u th , an d th e la g o o n a l s a lty c la y s o f th e V o ro ty s h c h a F o rm a tio n in th e n o rth. The S te b n y k F o rm a tio n is b u ilt o f m a in ly ro se, g re e n ish a n d g re y c a lc a re o u s m u d s to n e s in te rc a la te d w ith s e v e ra l v a ria b le s a n d s to n e b e d s, in c lu d in g th ic k-b e d d e d p a c k a g e s. Th e o c c u rre n c e o fte tra p o d fo o tp rin ts a n d ra in d ro p im p rin ts , a s w e ll a s th e o v e ra ll re d-b e d c h a ra c te r re fle c t p re v a ilin g c o n ti n e n ta l c o n d itio n s d u rin g d e p o s itio n o f th e fo rm a tio n , w h ic h is in te rp re te d a s s e d im e n ts o f a d e lta pla in w ith d is trib u ta ry c h a n n e ls in fille d w ith th ic k s a n d s to n e b e d s and a s s o c ia te d w ith in te rc a la tio n s o f th in n e r b e d s re fe rre d to c h a n n e l le v e e s an d c re v a s s e s p la y s. T h e u p p e r p a rt o f th e S te b n y k F o rm a tio n c o n ta in s m a rin e m ic ro fo s s ils o f th e N N 4 Z o n e , a n d lo c a lly o f th e N N 5 Z o n e , c o rre s p o n d in g to th e E arly B a d e n ia n tra n s g re s s io n in th e re g io n. O n a re g io n a l s c a le , th e S te b n y k F o rm a tio n s h o w s a p o la rity o f fa c ie s , w ith a la rg e c o n trib u tio n o f c o n g lo m e ra te s a n d th ic k-b e d d e d s a n d s to n e s in th e lo w e r p a rt in th e n o rth-w e s t a n d fin in g to th e s o u the a s t, w ith tra n s p o rt fro m th e w e s t a n d n o rth-w e s t. T h e s e d im e n ts a c c u m u la te d in an e lo n g a te d s u b s id in g z o n e b e tw e e n th e ris in g C a rp a th ia n o ro g e n a n d th e fo re b u lg e e le v a tio n o f th e fo re la n d , in w a rm an d s e m i-d ry c lim a tic c o n d itio n s c o rre s p o n d in g ro u g h ly to th e M id d le M io c e n e C lim a tic O p tim u m. T h e a c c u m u la tio n w a s b a l a n c e d by a s u b s id e n c e c a u s e d by s in k in g o f th e p la tfo rm s la b a n d by s e d im e n ta ry lo a d in g. K ey w o rd s : n o n-m a rin e , d e lta p lain , m o la s s e , M id d le M io c e n e C lim a tic O p tim u m , C a rp a th ia n F o re d e e p , U kra in e .

The prolonged interplay between orographic and climatic changes creates biogeographic barriers, resulting in the allopatric differentiation of plants in the Himalaya–Hengduan Mountains. Such consequences have led us to investigate the long-term Neogene–Quaternary geo-climatic history of the Eastern Himalaya–Hengduan Mountains. Narrowly distributed populations of Koenigia forrestii were sampled (ten populations, 97 individuals) and analysed for their genetic architecture, including phylogenetic reconstruction (based on plastome and plastid DNA/nuclear regions), molecular dating and demography, in combination with niche dynamics. We estimated that K. forrestii (stem age: 11.39 Mya) diverged into three non-overlapping distributed lineages during the Neogene–Quaternary periods (5.84–2.57 Mya), with Eastern Himalaya (EHa) being the first and most diverse lineage. ‘Isolation by environment’ revealed the existence of genetic structures that were significantly affected by the disparate envi...

With 788 species in 67 genera in the Neotropics, Arecaceae are an important ecological and economic component of the region. We review the influence of geological events such as the Pebas system, the Andean uplift and the land connections between South and Central/North America, on the historical assembly of Neotropical palms. We present a case study of the palm genus Astrocaryum (40 species) as a model for evaluating colonization and diversification patterns of lowland Neotropical taxa. We conducted a Bayesian dated phylogenetic analysis based on four low-copy nuclear DNA regions and a biogeographical analysis using the dispersal, extinction and cladogenesis model. Cladogenesis of Western Amazonian Astrocaryum spp. (c. 6 Mya) postdated the drainage of the aquatic Pebas system, supporting the constraining role of Pebas on in situ diversification and colonization. The ancestral distribution of Astrocaryum spp. in the Guiana Shield supported the hypothesis of an old formation that acted as a source area from which species colonized adjacent regions, but an earliest branching position for Guianan species was not confidently recovered. A twofold increase in diversification rate was found in a clade, the ancestor of which occupied the Guiana Shield (c. 13 Mya, a time of climatic change and Andean uplift).

The middle Miocene climate transition (MMCT) was a phase of global cooling possibly linked to decreasing levels of atmospheric CO 2. The MMCT coincided with the European Mammal Faunal Zone MN6. From this time, important biogeographic links between Anatolia and eastern Africa include the hominid Kenyapithecus. Vertebrate fossils suggested mixed open and forested landscapes under (sub)tropical seasonal climates for Anatolia. Here, we infer the palaeoclimate during the MMCT and the succeeding cooling phase for a middle Miocene (14.8-13.2 Ma) intramontane basin in southwestern Anatolia using three palaeobotanical proxies: (i) Köppen signatures based on the nearest living-relative principle; (ii) leaf physiognomy analysed with the Climate Leaf Analysis Multivariate Program (CLAMP); (iii) genus-level biogeographic affinities of fossil flora with modern regions. The three proxies reject tropical and hot subtropical climates for the MMCT of southwestern Anatolia and instead infer mild warm temperate C climates. Köppen signatures reject summer-dry Cs climates but cannot discriminate between fully humid Cf and winter-dry Cw; CLAMP reconstructs Cf climate based on the low X3.wet/X3.dry ratio. Additionally, we assess whether the palaeobotanical record resolves transitions from the warm Miocene Climatic Optimum (MCO, 16.8-14.7 Ma) to the MMCT (14.7-13.9 Ma), and a more pronounced cooling at 13.9-13.8 Ma, as reconstructed from benthic stable isotope data. For southwestern Anatolia, we find that arboreal taxa predominate in MCO flora (MN5), whereas in MMCT flora (MN6) abundances of arboreal and non-arboreal elements strongly fluctuate, indicating higher structural complexity of the vegetation. Our data show a distinct pollen zone between MN6 and MN7 + 8 dominated by herbaceous taxa. The boundary between MN6 and MN7 + 8, roughly corresponding to a first abrupt cooling at 13.9-13.8 Ma, might be associated with this herb-rich pollen zone.

The middle Miocene climate transition (MMCT) was a phase of global cooling possibly linked to decreasing levels of atmospheric CO 2 . The MMCT coincided with the European Mammal Faunal Zone MN6. From this time, important biogeographic links between Anatolia and eastern Africa include the hominid Kenyapithecus. Vertebrate fossils suggested mixed open and forested landscapes under (sub)tropical seasonal climates for Anatolia. Here, we infer the palaeoclimate during the MMCT and the succeeding cooling phase for a middle Miocene (14.8-13.2 Ma) intramontane basin in southwestern Anatolia using three palaeobotanical proxies: (i) Köppen signatures based on the nearest living-relative principle; (ii) leaf physiognomy analysed with the Climate Leaf Analysis Multivariate Program (CLAMP); (iii) genus-level biogeographic affinities of fossil flora with modern regions. The three proxies reject tropical and hot subtropical climates for the MMCT of southwestern Anatolia and instead infer mild warm temperate C climates. Köppen signatures reject summer-dry Cs climates but cannot discriminate between fully humid Cf and winter-dry Cw; CLAMP reconstructs Cf climate based on the low X3.wet/X3.dry ratio. Additionally, we assess whether the palaeobotanical record resolves transitions from the warm Miocene Climatic Optimum (MCO, 16.8-14.7 Ma) to the MMCT (14.7-13.9 Ma), and a more pronounced cooling at 13.9-13.8 Ma, as reconstructed from benthic stable isotope data. For southwestern Anatolia, we find that arboreal taxa predominate in MCO flora (MN5), whereas in MMCT flora (MN6) abundances of arboreal and non-arboreal elements strongly fluctuate, indicating higher structural complexity of the vegetation. Our data show a distinct pollen zone between MN6 and MN7 + 8 dominated by herbaceous taxa. The boundary between MN6 and MN7 + 8, roughly corresponding to a first abrupt cooling at 13.9-13.8 Ma, might be associated with this herb-rich pollen zone.

The middle Miocene climate transition (MMCT) was a phase of global cooling possibly linked to decreasing levels of atmospheric CO 2. The MMCT coincided with the European Mammal Faunal Zone MN6. From this time, important biogeographic links between Anatolia and eastern Africa include the hominid Kenyapithecus. Vertebrate fossils suggested mixed open and forested landscapes under (sub)tropical seasonal climates for Anatolia. Here, we infer the palaeoclimate during the MMCT and the succeeding cooling phase for a middle Miocene (14.8–13.2 Ma) intra-montane basin in southwestern Anatolia using three palaeob-otanical proxies: (i) Köppen signatures based on the nearest living-relative principle; (ii) leaf physiognomy analysed with the Climate Leaf Analysis Multivariate Program (CLAMP); (iii) genus-level biogeographic affinities of fossil flora with modern regions. The three proxies reject tropical and hot subtropical climates for the MMCT of southwestern Anatolia and instead infer mild warm temperate C climates. Köppen signatures reject summer-dry Cs climates but cannot discriminate between fully humid Cf and winter-dry Cw; CLAMP reconstructs Cf climate based on the low X3.wet/X3.dry ratio. Additionally, we assess whether the palaeobotanical record resolves transitions from the warm Miocene Climatic Optimum (MCO, 16.8–14.7 Ma) to the MMCT (14.7– 13.9 Ma), and a more pronounced cooling at 13.9–13.8 Ma, as reconstructed from benthic stable isotope data. For southwestern Anatolia, we find that arboreal taxa predominate in MCO flora (MN5), whereas in MMCT flora (MN6) abundances of arboreal and non-arboreal elements strongly fluctuate , indicating higher structural complexity of the vegetation. Our data show a distinct pollen zone between MN6 and MN7 + 8 dominated by herbaceous taxa. The boundary between MN6 and MN7 + 8, roughly corresponding to a first abrupt cooling at 13.9–13.8 Ma, might be associated with this herb-rich pollen zone.

The Shangwang Basin is a small Cenozoic sedimentary basin located in Linqu county,  Shangdong Province. The Shangwang Formation, especially the diatomaceous shale member, contains diverse and finely preserved flora and fauna fossils. Previous paleontological study and radiometric dating show it was formed in the Miocene. However, on the precise age of the formation,  there are such different opinions as late Miocene, middle Miocene, or early stage of the Middle Miocene.

We have refined the age of the Shangwang Formation by means of geomagnetic polarity data combined with the latest results of radiometric dating as well as palynological analysis.

The Integrated Plant Record vegetation analysis (IPR vegetation analysis) is a semi-quantitative method that has been developed to reconstruct Cenozoic zonal vegetation based on the fossil leaf, fruit, and pollen record, i.e., the integrated plant record. To date, thousands of taxa have been scored and more than 300 fossil and modern plant sites have been evaluated by this method. Such huge amounts of data can be handled easily and made widely available only by a sophisticated, automated working application. The internet platform www.iprdatabase.eu provides an interactive database of scored taxa, localities, and a template for the evaluation of further plant assemblages , whether fossil or modern. Moreover, the computerised application allows changing classification parameters, directly editing synonyms and typographical errors, as well as scoring taxa within formerly uploaded datasets. To keep the database operational, the above-mentioned inputs are possible only under an authorised access to the application.