Competition among species and entire clades can impact species diversification and extinction, which can shape macroevolutionary patterns. The fossil record shows successive biotic turnovers such that a dominant group is replaced by another. One striking example involves the decline of gymnosperms and the rapid diversification and ecological dominance of angiosperms in the Cretaceous. It is generally believed that angiosperms outcompeted gymnosperms, but the macroevolutionary processes and alternative drivers explaining this pattern remain elusive. Using extant time trees and vetted fossil occurrences for conifers, we tested the hypotheses that clade competition or climate change led to the decline of conifers at the expense of angiosperms. Here, we find that both fossil and molecular data show high congruence in revealing 1) low diversification rates, punctuated by speciation pulses, during warming events throughout the Phanerozoic and 2) that conifer extinction increased significantly in the Mid-Cretaceous (100 to 110 Ma) and remained high ever since. Their extinction rates are best explained by the rise of angiosperms, rejecting alternative models based on either climate change or time alone. Our results support the hypothesis of an active clade replacement, implying that direct competition with angiosperms increased the extinction of conifers by pushing their remaining species diversity and dominance out of the warm tropics. This study illustrates how entire branches on the Tree of Life may actively compete for ecological dominance under changing climates.

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Sequence stratigraphic interpretation of paralic successions is complicated by the complex interfingering of marine and continental strata. The successions may also include terrestrial extensions of marine parasequences and completely independent lacustrine parasequence analogues. Failure in recognizing the possible interbeddding of these two independent parasequence types may lead to construction of sequence stratigraphic schemes based on incompatible data sets. We have studied a Lower Jurassic paralic section from the Baltic island of Bornholm, situated in the Tornquist Zone, which demarcates the transition from the stable Precambrian Baltic Shield to the subsiding Danish Basin and Danish‐Polish Trough. The Hettangian‐Sinemurian Sose Bugt Member (Rønne Formation) of Bornholm includes lacustrine, fluvial and restricted marine, estuarine deposits reflecting the basin‐margin position. Biostatigraphic resolution is poor and a sequence stratigraphic interpretation of the paralic succession is far from straightforward. A multidisciplinary approach including facies analysis, recognition and lateral trading of key surfaces, palynostratigraphy, palynofacies, coal petrography, palaeopedology, clay mineralogy and source rock geochemistry is applied in order to obtain a high degree of precision in the interpretation of the paralic facies. In this way four sequences are recognized in the overall backstepping lacustrine to estuarine succession. Marine and marginal marine parasequences are distinguished from their purely lacustrine analogues, and an internally consistent sequence stratigraphic scheme is proposed. This is compared and tentatively correlated with fossiliferous marine sediments in the Danish Basin and with published eustatic cycle charts.

The abundance of dinosaur eggs in Upper Cretaceous strata of Henan Province, China led to the collection and export of countless such fossils. One of these specimens, recently repatriated to China, is a partial clutch of large dinosaur eggs (Macroelongatoolithus) with a closely associated small theropod skeleton. Here we identify the specimen as an embryo and eggs of a new, large caenagnathid oviraptorosaur, Beibeilong sinensis. This specimen is the first known association between skeletal remains and eggs of caenagnathids. Caenagnathids and oviraptorids share similarities in their eggs and clutches, although the eggs of Beibeilong are significantly larger than those of oviraptorids and indicate an adult body size comparable to a gigantic caenagnathid. An abundance of Macroelongatoolithus eggs reported from Asia and North America contrasts with the dearth of giant caenagnathid skeletal remains. Regardless, the large caenagnathid-Macroelongatoolithus association revealed here suggests these dinosaurs were relatively common during the early Late Cretaceous.

Structure of the manus and pes has long been a source of confusion in ankylosaurs