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Redescription of neoceratopsian dinosaur Archaeoceratops and early evolution of Neoceratopsia

100%

You H., Dodson P.

Acta Palaeontologica Polonica

2003

tom 48

nr 2

Archaeoceratops oshimai Dong and Azuma, 1997 is a basal neoceratopsian from the late Early Cretaceous of Mazongshan area, Gansu Province, northwest China. Here we provide a detailed description on Archaeoceratops oshimai based on both the holotype, which consists of a well preserved, nearly complete skull, partial vertebral column, and partial pelvis, and the paratype, which consists of a partial vertebral column including a nearly complete tail, a partial pelvis, fragmentary hind limb bones, and a complete pes. Cladistic analysis shows that Archaeoceratopsis the sister group to all currently known Late Cretaceous Neoceratopsia, and Late Cretaceous Neoceratopsia diverged into two clades: the Asian Protoceratopsidae and the North American Ceratopsoidea, indicating a dual evolution for the two major groups of horned dinosaurs in two landmasses of Late Cretaceous. A suite of derived features characterizes Ceratopsoidea, such as a round−shaped external naris, a long caudolateral process of the rostral bone, and ventrally curved premaxillary ventral edge.

The cellular pathway and enzymatic activity for phloem-unloading transition in developing Camellia oleifera Abel. Fruit

71%

Wang X., You H., Yuan Y., Zhang H., Zhang L.

Acta Physiologiae Plantarum

2018

tom 40

nr 02

The phloem-unloading pathway of sucrose and mechanism of sugar-to-oil transition are still unknown in Camellia oleifera Fruit. Here, transmission electronic microscopy (TEM) and confocal laser-scanning microscopy (CLSM) were used to observe the cellular structure of vascular bundles and symplastic tracer, carboxyfluorescein (CF), transport in phloem zone. The results showed that sucrose was transported via symplast system in the early and late phases, whereas apoplast system exerted the function in middle stage. Moreover, enzymatic assays showed that acid invertase had a higher activity at the transition stage during the whole fruit development. The cell wall bound invertase (CWI) activity reached the highest at the middle stage of fruit development and the switch in phloem-unloading coincided with fruit developmental phase change and oil accumulation. Correlation analysis showed that the oil accumulation was significantly negatively correlated with content of soluble sugar at P < 0.05 level. However, the soluble acid invertase (SAI), CWI, and neutral invertase showed a significant positive correlation with oil accumulation at P < 0.01 level. In summary, our data provide new cytological insights into the transition of unloading transfer between symplasmic and apoplasmic patterns in C. oleifera fruit and suggest that invertases are positively involved in sugar–oil transition process.

A new basal eusauropod from the Middle Jurassic of Yunnan, China, and faunal compositions and transitions of Asian sauropodomorph dinosaurs

61%

Xing L., Miyashita T., Currie P. J., You H., Zhang J., Dong Z.

Acta Palaeontologica Polonica

2015

tom 60

nr 1

Many sauropod ghost lineages cross the Middle Jurassic, indicating a time interval that requires increased sampling. A wide taxonomic spectrum of sauropodomorphs is known from the Middle Jurassic of China, but the braincase of a new sauropod, named here Nebulasaurus taito gen. et sp. nov., is distinct. Nebulasaurus is sister taxon to Spinophorosaurus from the Middle Jurassic of Africa and represents a clade of basal eusauropods previously unknown from Asia. The revised faunal list indicates dramatic transitions in sauropodomorph faunas from the Jurassic to Cretaceous of Asia; these are consistent with geographic isolation of Asia through the Late Jurassic. Non-sauropod sauropodomorphs, non-mamenchisaurid eusauropods (including basal macronarians), and mamenchisaurids successively replaced previous grades through the Jurassic, and titanosauriforms excluded all other sauropod lineages across the Jurassic–Cretaceous boundary.

Ograniczanie wyników

2 Acta Palaeontologica Polonica

1 Acta Physiologiae Plantarum

3 You H.

1 Currie P. J.

1 Dodson P.

1 Dong Z.

1 Miyashita T.

1 Wang X.

1 Xing L.

1 Yuan Y.

1 Zhang H.

1 Zhang J.

1 Zhang L.

1 2018

1 2015

1 2003

Wyniki wyszukiwania

Redescription of neoceratopsian dinosaur Archaeoceratops and early evolution of Neoceratopsia

The cellular pathway and enzymatic activity for phloem-unloading transition in developing Camellia oleifera Abel. Fruit

A new basal eusauropod from the Middle Jurassic of Yunnan, China, and faunal compositions and transitions of Asian sauropodomorph dinosaurs