| Parmelia ambra | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Ascomycota |
| Class: | Lecanoromycetes |
| Order: | Lecanorales |
| Family: | Parmeliaceae |
| Genus: | Parmelia |
| Species: | †P. ambra |
| Binomial name | |
| †Parmelia ambra Poinar, E.B.Peterson & Platt (2000) | |
Parmelia ambra is a fossilised species of foliose lichen in the family Parmeliaceae. Found in Dominican amber and described as a new species in 2000, the fossil has been used in subsequent studies of lichen evolution.
The fossil was discovered in Dominican amber and formally described as a new species in 2000 by George Poinar Jr., Eric Peterson, and Jamie Platt. Because of its resemblance to modern-day members of Parmelia , it has been placed provisionally in that genus, although the authors acknowledge that without sacrificing more of the specimen for analysis, it is impossible to assert this definitively. [1]
Based on what types of organisms are used for dating, Dominican amber dates from 15–20 million years ago (based on foraminifera fossils), to 30–45 million years (based on coccolith fossils). [1] Because lichens are scarce in the fossil record, specimens like this are often used as calibration points for molecular clock analyses to improve understanding of lichen evolution. [2] [3] [4]
The fossil lichen has a thallus comprising dichotomously branched lobes with a thickness of 30–50 μm. The upper thallus surface is smooth and lighter in colour than the lower surface, which is black with dark rhizines measuring 0.5–0.9 mm long. Neither apothecia nor pycnidia are apparent on the fossil. A single isidium is present, with a length of 110 μm and diameter of 50 μm. The hyphae of the medulla are thick-walled, loosely interwoven, and have a diameter of 0.8–2.3 μm. Algal cells, rounded to somewhat elliptic in shape and measuring 5.8–11.6 μm, are present at the interface between the cortex and the medulla. [1]
Parmelia is a genus of medium to large foliose lichens. It has a global distribution, extending from the Arctic to the Antarctic continent but concentrated in temperate regions. There are about 40 species in Parmelia. In recent decades, the once large genus Parmelia has been divided into a number of smaller genera according to thallus morphology and phylogenetic relatedness.
The Parmeliaceae is a large and diverse family of Lecanoromycetes. With over 2700 species in 71 genera, it is the largest family of lichen-forming fungi. The most speciose genera in the family are the well-known groups: Xanthoparmelia, Usnea, Parmotrema, and Hypotrachyna.
Parmelia sulcata is a foliose lichen in the family Parmeliaceae. It is very tolerant of pollution and has a cosmopolitan distribution, making it one of the most common lichens. It harbours a unicellular Trebouxia green algal symbiont.
Melanohalea is a genus of foliose lichens in the family Parmeliaceae. It contains 30 mostly Northern Hemisphere species that grow on bark or on wood. The genus is characterized by the presence of pseudocyphellae, usually on warts or on the tips of isidia, a non-pored epicortex and a medulla containing depsidones or lacking secondary compounds. Melanohalea was circumscribed in 2004 as a segregate of the morphologically similar genus Melanelia.
Melanelixia is a genus of foliose lichens in the family Parmeliaceae. It contains 15 Northern Hemisphere species that grow on bark or on wood. The genus is characterized by a pored or fenestrate epicortex, and the production of lecanoric acid as the primary chemical constituent of the medulla. Melanelixia was circumscribed in 2004 as a segregate of the related genus Melanelia.
Punctelia is a genus of foliose lichens belonging to the large family Parmeliaceae. The genus, which contains about 50 species, was segregated from genus Parmelia in 1982. Characteristics that define Punctelia include the presence of hook-like to thread-like conidia, simple rhizines, and point-like pseudocyphellae. It is this last feature that is alluded to in the vernacular names speckled shield lichens or speckleback lichens.
Everniopsis is a fungal genus in the family Parmeliaceae. It consists of a single species, the bark-dwelling lichen Everniopsis trulla, which occurs in Africa and South America.
Crespoa is a genus of five species of lichen in the family Parmeliaceae. Species in this genus are characterized by having an upper thallus surface that is wrinkled and reticulately ridged to coarsely foveolate.
Emodomelanelia is a lichen genus in the family Parmeliaceae. It is monotypic, containing the single foliose Himalayan species Emodomelanelia masonii.
Notoparmelia is a genus of foliose lichens in the family Parmeliaceae. It includes 18 species that grow on bark and rocks, and are mostly distributed in the Southern Hemisphere. The genus was created in 2014 as a segregate of Parmelia.
Austromelanelixia is a genus of five species of foliose lichens in the family Parmeliaceae. All species are found in the Southern Hemisphere.
Montanelia is a genus of lichenized fungi belonging to the family Parmeliaceae. It was circumscribed by Pradeep K. Divakar, Ana Crespo, Mats Wedin, and Theodore L. Esslinger in 2012 to accommodate a group of five species previously assigned to the genus Melanelia.
Punctelia subflava is a species of foliose lichen in the family Parmeliaceae that occurs in Australia.
Parmelia mayi is a species of foliose lichen in the family Parmeliaceae. It is found in the northern Appalachian Mountains of eastern North America, where it grows on rocks and on the trunks of paper birch and balsam fir. Parmelia mayi is morphologically indistinguishable from Parmelia saxatilis, but is distinct in its distribution, chemistry, and genetics.
Parmelia barrenoae is a species of foliose lichen in the large family Parmeliaceae. It was formally described as a new species in 2005. Before this, it was lumped together as one of several lichens in the Parmelia sulcata group—a species complex of genetically distinct lookalikes. Parmelia barrenoae is widely distributed, occurring in Europe, western North America, Africa, and Asia.
Parmelia fraudans is a species of foliose lichen in the family Parmeliaceae. It is found in Europe and North America, where it grows on rocks.
Parmelia imbricaria is a species of foliose lichen in the family Parmeliaceae. Found in western Canada, it was formally described as a new species in 2017 by Trevor Goward, Pradeep Kumar Divakar, María del Carmen Molina, and Ana Crespo. The type specimen was collected by Goward near the Clearwater River drainage, where it was found at an altitude of 700 m (2,300 ft) growing on a basalt boulder. The specific epithet refers to the "imbricate" lobes of the thallus. The lichen occurs in western Canada, with a range including southern Yukon and extending south to southern inland British Columbia. The European Parmelia pinatifida is a closely related species.
Neoprotoparmelia capitata is a species of corticolous (bark-dwelling) and crustose lichen in the family Parmeliaceae. It is found in eastern North America.
Parmelia encryptata is a species of corticolous (bark-dwelling), foliose lichen in the family Parmeliaceae. Found in the Iberian Peninsula, it was formally described as a new species in 2011 by Ana Crespo, Pradeep Kumar Divakar, and Maria del Carmen Molina. It is cryptic species that is a member of the Parmelia sulcata species complex, and it is morphologically indistinguishable from that lichen. Molecular phylogenetic analysis, however, shows that it is a genetically unique species originating from a different lineage. Parmelia encryptata has been estimated to have diverged from the P. squarrosa complex about 5.4 million years ago.
Parmelia isidiiveteris is a fossilised species of foliose lichen in the family Parmeliaceae. It was found in Dominican amber and described as a new species in 2000. It was tentatively placed in the genus Parmelia although its true generic placement is difficult to determine with only a single specimen available for analysis.