Cheirolepidiaceae is a family of extinct coniferous plants that had a global distribution 259.0 to 61.7 Ma.[1]

This family of conifers, superficially similar to Cupressaceae, was a significant part of the flora of the Mesozoic, around 252 to 66 million years ago.[2] They are united by the possession of a distinctive pollen type assigned to the form genus Classopollis. The name Frenelopsidaceae (as a separate family) or "frenelopsids" has been used for a group of Cheirolepidiaceae with jointed stems, thick internode cuticles, sheathing leaf bases and reduced free leaf tips.

Some species are thought to have been the first plants to be insect pollinated as they occur in association with extinct pollinating scorpionflies.[3]

The family name Hirmeriellaceae is a junior synonym of Cheirolepidiaceae.[4]

Temporal range: Mesozoic
Main floristic types from the Danian - journal.pone.0052455.g007-right
Cheirolepidiaceae in a Danian landscape (reconstruction by F. Guillén)
Scientific classification
Kingdom: Plantae
Division: Pinophyta
Class: Pinopsida
Order: Pinales
Family: Cheirolepidiaceae
Turutanova-Ketova 1963
  • Brachyoxylon
  • Classopollis
  • Cupressinocladus
  • Dicheiropollis
  • Frenelopsis
  • Pseudofrenelopsis
  • Watsoniocladus


  1. ^ "†family Cheirolepidiaceae". Fossilworks. Retrieved 11 February 2018.
  2. ^ Axsmith, B. J.; Krings, M.; Waselkov, K. (2004). "Conifer pollen cones from the Cretaceous of Arkansas: implications for diversity and reproduction in the Cheirolepidiaceae" (PDF). Journal of Paleontology. 78 (2): 402–409. doi:10.1666/0022-3360(2004)078<0402:CPCFTC>2.0.CO;2. Retrieved 11 February 2011.
  3. ^ Ren D, Labandeira CC, Santiago-Blay JA, Rasnitsyn A, Shih CK, Bashkuev A, Logan MA, Hotton CL, Dilcher D. (2009). Probable Pollination Mode Before Angiosperms: Eurasian, Long-Proboscid Scorpionflies. Science, 326 (5954), 840-847.doi:10.1126/science.1178338
  4. ^ Herendeen, P., 2015. Report of the nomenclature committee on fossils. 9. Taxon (64) 6: 1306-1312

Ampezzoa triassica is an extinct species of gall mite described from the Carnian of northeastern Italy. It lived as a parasite of Cheirolepidiaceae trees. The only known specimen, preserved in amber, is 0.124 mm long. It resembles very much, in body shape and wax secretions, the contemporary gall mite Cymeda zealandica. Along with Triasacarus fedelei and an unnamed dipteran, it is the oldest arthropod found enclosed in amber.Ampezzoa had a vagrant lifestyle on the surface of its host. It secreted waxy filaments, as a defense against predation and desiccation.


Baikuris is an extinct genus of ant in the Formicidae subfamily Sphecomyrminae, and is currently placed in the tribe Sphecomyrmini. The genus contains four described species: the type species Baikuris mandibularis, along with Baikuris casei, Baikuris maximus, and Baikuris mirabilis.


Brachyphyllum is a form genus of fossil coniferous plant foliage. Plants of the genus have been variously assigned to several different conifer groups including Araucariaceae and Cheirolepidiaceae. They are known from around the globe from the Late Carboniferous to the Late Cretaceous periods.

Cañadón Asfalto Formation

The Cañadón Asfalto Formation is a Early Jurassic to Middle Jurassic geologic formation, from the Jurassic period of the Mesozoic Era. It was formerly thought to be Mid to Late Jurassic in age, but Uranium-Lead dating of the volcanic tuff beds have revised the age to the mid Toarcian to sometime in the Mid Jurassic, probably the Bajocian.It is located in the Cañadón Asfalto Basin, a rift basin in Chubut Province of northwestern Patagonia, in southern Argentina. The basin started forming in the earliest Jurassic.It is composed of fluvial-lacustrine deposits, typically sandstones and shales with a saline paleolake carbonate evaporitic sequence of limestone in its lowest Las Chacritas Member. Interbedded with these are volcanic tuffites. It is divided into two members, the Las Chacritas Member, and the overlying Puesto Almada member, but the latter has also been assigned to the overlying Cañadón Calcáreo Formation by other authors.According to a palynological study the dominant pollen was produced by the conifer families Cheirolepidiaceae (Classopollis) and Araucariaceae (mainly Araucariacites and Callialasporites), suggesting that warm-temperate and relatively humid conditions under highly seasonal climate prevailed during the depositional times of the unit. The abundance of Botryococcus supports the presence of a shallow lake with probably saline conditions.

Cañadón Calcáreo Formation

The Cañadón Calcáreo Formation is a Oxfordian to Kimmeridgian-aged geologic formation, from the Cañadón Asfalto Basin in Chubut Province, Argentina, a rift basin that started forming since the earliest Jurassic. It was formerly thought to date into the Cretaceous, but the age has been revised with Uranium Lead dating as likely being solely Late Jurassic in age.It is a subunit of the Loco Trapial Group, close to the city Cerro Condor in the Chubut Province of northwestern Patagonia, in southern Argentina. The formation is composed primarily of fluvial sandstones alongside shales and volcanic tuffitesThe formation preserves fishes, crocodylomorphs and some dinosaur taxa, as well as conifers.

Drzewica Formation

The Drzewica Formation is a geologic formation in Szydłowiec, Poland. It is late Pliensbachian age. Vertebrate fossils have been uncovered from this formation. The stathigraphic setting of the dinosaur tracks reported from the formation suggest a foreshore/fluvial barrier. Body fossils reported include bivalves, palynology, fossil trunks, roots. Trunks of coniferous wood, especially Cheirolepidiaceae and Taxodiaceae trees (with the possibility of early yet gigantic Sequoioideae members) show the occurrence of vast coniferous forests around the tracksite. The association of gigantic forests and dinosaur megafauna on the Pliensbachian suggests also a colder and specially damp ecosystem. As many studies of the formation share, Drzewica shows in part to be a gigantic shore barrel, setting at the time where the Polish basin sea was at its lowest point. Other related units are Fjerritslev or Gassum Formation (Danish Basin), lower Bagå Formation (Bornholm), upper Neringa Formation (Lithuania). Abandoned informal units in Poland: upper Sawêcin beds, Wieluñ series, Bronów series..


Hirmeriella is a genus of fossil tree, a conifer that was widespread in Late Triassic and Early Jurassic of Germany, the UK, and Poland. It is common in the fissure fills of Glamorgan, south Wales, where many of the UK's earliest mammal fossils have been found such as Morganucodon.The name Hirmeriella muensteri has now been used to describe the whole plant, but it may also specifically refer to fossils of female parts of the plant, while male parts of the conifer may be known by the scientific name Brachyphyllum muensteri, and fossils with neither gender parts have been known as Pagiophyllum. Hirmeriella is also known by the pseudonym Cheirolepis muensteri.Hirmeriella muensteri may have grown in dry, extreme conditions, and been fire tolerant, although other authors have cited evidence from water wicking leaves as signs they were found in humid, water rich environments.


The Jurassic period (; from Jura Mountains) is a geologic period and system that spanned 56 million years from the end of the Triassic Period 201.3 million years ago (Mya) to the beginning of the Cretaceous Period 145 Mya. The Jurassic constitutes the middle period of the Mesozoic Era, also known as the Age of Reptiles. The start of the period was marked by the major Triassic–Jurassic extinction event. Two other extinction events occurred during the period: the Pliensbachian-Toarcian extinction in the Early Jurassic, and the Tithonian event at the end; neither event ranks among the "Big Five" mass extinctions, however.

The Jurassic period is divided into three epochs: Early, Middle, and Late. Similarly, in stratigraphy, the Jurassic is divided into the Lower Jurassic, Middle Jurassic, and Upper Jurassic series of rock formations.

The Jurassic is named after the Jura Mountains within the European Alps, where limestone strata from the period were first identified.

By the beginning of the Jurassic, the supercontinent Pangaea had begun rifting into two landmasses: Laurasia to the north, and Gondwana to the south. This created more coastlines and shifted the continental climate from dry to humid, and many of the arid deserts of the Triassic were replaced by lush rainforests.

On land, the fauna transitioned from the Triassic fauna, dominated by both dinosauromorph and crocodylomorph archosaurs, to one dominated by dinosaurs alone. The first birds also appeared during the Jurassic, having evolved from a branch of theropod dinosaurs. Other major events include the appearance of the earliest lizards, and the evolution of therian mammals, including primitive placentals. Crocodilians made the transition from a terrestrial to an aquatic mode of life. The oceans were inhabited by marine reptiles such as ichthyosaurs and plesiosaurs, while pterosaurs were the dominant flying vertebrates.


Kalligrammatidae, sometimes known as kalligrammatids or kalligrammatid lacewings, is a family of extinct insects in the order Neuroptera (lacewings) that contains twenty genera and a number of species. The family lived from the Middle Jurassic to the Early Middle Cretaceous before going extinct. Species of the family are known from Europe, Asia, and South America. The family has been occasionally described as "butterflies of the Jurassic" based on their resemblance to modern butterflies in morphology and ecological niche.


Mecoptera (from the Greek: mecos = "long", ptera = "wings") are an order of insects in the superorder Endopterygota with about six hundred species in nine families worldwide. Mecopterans are sometimes called scorpionflies after their largest family, Panorpidae, in which the males have enlarged genitals that look similar to the stingers of scorpions, and long beaklike rostra. The Bittacidae, or hangingflies, are another prominent family and are known for their elaborate mating rituals, in which females choose mates based on the quality of gift prey offered to them by the males. A smaller group is the snow scorpionflies, family Boreidae, adults of which are sometimes seen walking on snowfields. In contrast, the majority of species in the order inhabit moist environments in tropical locations.

The Mecoptera are closely related to the Siphonaptera (fleas), and a little more distantly to the Diptera (true flies). They are somewhat fly-like in appearance, being small to medium-sized insects with long slender bodies and narrow membranous wings. Most breed in moist environments such as leaf litter or moss, and the eggs may not hatch until the wet season arrives. The larvae are caterpillar-like and mostly feed on vegetable matter, and the non-feeding pupae may pass through a diapause until weather conditions are favorable.

Early Mecoptera may have played an important role in pollinating extinct species of gymnosperms before the evolution of other insect pollinators such as bees. Adults of modern species are overwhelmingly predators or consumers of dead organisms; they are the first insects to arrive at a cadaver, making them useful in forensic entomology.


Pagiophyllum is a form genus of fossil coniferous plant foliage. Plants of the genus have been variously assigned to several different conifer groups including Araucariaceae and Cheirolepidiaceae. They were found around the globe during the Carboniferous to the Cretaceous period.

Paja Formation

The Paja Formation is a Mesozoic geologic formation from the Aptian epochs of the Early Cretaceous of central Colombia, extending on the Altiplano Cundiboyacense in the Eastern Ranges of the Colombian Andes in the departments of Cundinamarca, Santander and Boyacá. It mainly composed of mudrocks with nodules of sandstones and limestones, that are interpreted as part of a marginal marine deposit, with anoxic zones, in the warm and shallow sea that covered most of the Colombian territory during the Cretaceous. Plesiosaur, ichthyosaur, sea turtles, teleostean fishes and ammonites remains are among the main fossils that have been recovered from its strata, mainly near to the modern town of Villa de Leiva in Boyacá.


The order Pinales in the division Pinophyta, class Pinopsida, comprises all the extant conifers. This order used to be known as the Coniferales.The distinguishing characteristic is the reproductive structure known as a cone produced by all Pinales. All of the extant conifers, such as cedar, celery-pine, cypress, fir, juniper, larch, pine, redwood, spruce, and yew, are included here. Some fossil conifers, however, belong to other distinct orders within the division Pinophyta.

The yews had been separated into a distinct order of their own (Taxales), but genetic evidence indicates yews are monophyletic with other conifers and they are now included in the Pinales.

The families included are the Araucariaceae, Cupressaceae, Pinaceae, Podocarpaceae, Sciadopityaceae, and Taxaceae.


Rahiolisaurus is a genus of abelisaurid theropod dinosaur which existed in India during the Late Cretaceous period. It was described in 2010, based on fossils recovered from the Lameta Formation in the Indian state of Gujarat. These fossils include elements from at least seven different individuals and are believed to have been from the Maastrichtian stage, sometime between 72.1 and 66 million years ago. Despite representing a variety of different growth stages, all recovered fossils from the locality indicate a single species, the type species Rahiolisaurus gujaratensis.


Rajasaurus is a genus of carnivorous abelisaurid theropod dinosaur from the Late Cretaceous of India, containing one species: Rajasaurus narmadensis. The bones were excavated from the Lameta Formation in the Gujarat state of Western India, probably inhabiting what is now the Narmada River Valley. It was formally described by palaeontologist Jeffrey A. Wilson and colleagues in 2003 based on a partial skeleton comprising the braincase, spine, hip bone, legs, and tail–a first for an Indian theropod. The dinosaur likely measured 6.6 metres (22 ft), and had a single horn on the forehead which was probably used for display and head-butting. Like other abelisaurids, Rajasaurus was probably an ambush predator.

India at this time was an island, due to the break-up of the supercontinent Gondwana, though it is possible animals still were able to migrate to and from nearby continents. The creation of the subfamily Majungasaurinae, and its inclusion of abelisaurids from India, Madagascar, and Europe–including Rajasaurus–further reiterates this. The Lameta Formation has yielded several other dinosaur species, including abelisaurids and titanosaurian sauropods, similar to other Gondwanan landmasses. The area during the Cretaceous was probably forested, and served as a nesting grounds for several creatures. Rajasaurus has become a tourist attraction for the state of Gujarat.

Timeline of plant evolution

This article attempts to place key plant innovations in a geological context. It concerns itself only with novel adaptations and events that had a major ecological significance, not those that are of solely anthropological interest. The timeline displays a graphical representation of the adaptations; the text attempts to explain the nature and robustness of the evidence.

Plant evolution is an aspect of the study of biological evolution, predominantly involving evolution of plants suited to live on land, greening of various land masses by the filling of their niches with land plants, and diversification of groups of land plants.


Triasacarus fedelei is an extinct species of gall mite described from the Carnian of northeastern Italy. It lived as a parasite of Cheirolepidiaceae trees. The only known specimen, preserved in amber, is 0.210 mm long. Along with Ampezzoa triassica and an unnamed dipteran, it is the oldest arthropod found enclosed in amber.It is possible that Triasacarus induced the formation of galls on the host plant.


Voltziales is an extinct order of trees related to modern conifers. In the fossil record, the most common member of the order is Walchia, known originally for its leaf form genus, and the order is commonly called Walchian. The order consists of these families:









Wessex Formation

The Wessex Formation is a fossil-rich English geological formation that dates from the Berriasian to Barremian stages (about 145–125 million years ago) of the Early Cretaceous. It forms part of the Wealden Group and underlies the younger Vectis Formation and overlies the Durlston Formation. The dominant lithology of this unit is mudstone with some interbedded sandstones.


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